Programs & Examples On #Nawk

`nawk` is a pattern scanning and processing language.

configure: error: C compiler cannot create executables

I furiously read all of this page, hoping to find a solution for:

"configure: error: C compiler cannot create executables"

In the end nothing worked, because my problem was a "typing" one, and was related to CFLAGS. In my .bash_profile file I had:

export ARM_ARCH="arm64”
export CFLAGS="-arch ${ARM_ARCH}"

As you can observe --- export ARM_ARCH="arm64” --- the last quote sign is not the same with the first quote sign. The first one ( " ) is legal while the second one ( ” ) is not.
This happended because I made the mistake to use TextEdit (I'm working under MacOS), and this is apparently a feature called SmartQuotes: the quote sign CHANGES BY ITSELF TO THE ILLEGAL STYLE whenever you edit something just next to it.
Lesson learned: use a proper text editor...

What is "pass-through authentication" in IIS 7?

Normally, IIS would use the process identity (the user account it is running the worker process as) to access protected resources like file system or network.

With passthrough authentication, IIS will attempt to use the actual identity of the user when accessing protected resources.

If the user is not authenticated, IIS will use the application pool identity instead. If pool identity is set to NetworkService or LocalSystem, the actual Windows account used is the computer account.

The IIS warning you see is not an error, it's just a warning. The actual check will be performed at execution time, and if it fails, it'll show up in the log.

git - Your branch is ahead of 'origin/master' by 1 commit

I resolved this by just running a simple:

git pull

Nothing more. Now it's showing:

# On branch master
nothing to commit, working directory clean

How to create JSON string in JavaScript?

This can be pretty easy and simple

var obj = new Object(); = "Raj";
obj.age = 32;
obj.married = false;

//convert object to json string
var string = JSON.stringify(obj);

//convert string to Json Object
console.log(JSON.parse(string)); // this is your requirement.

Cloudfront custom-origin distribution returns 502 "ERROR The request could not be satisfied." for some URLs

In our case, everything LOOKED ok, but it took most of the day to figure this out:

TLDR: Check your certificate paths to make sure the root certificate is correct. In the case of COMODO certificates, it should say "USERTrust" and be issued by "AddTrust External CA Root". NOT "COMODO" issued by "COMODO RSA Certification Authority".

From the CloudFront docs:

If the origin server returns an invalid certificate or a self-signed certificate, or if the origin server returns the certificate chain in the wrong order, CloudFront drops the TCP connection, returns HTTP error code 502, and sets the X-Cache header to Error from cloudfront.

We had the right ciphers enabled as per:

Our certificate was valid according to Google, Firefox and ssl-checker:

SSL Checker result without all required certificates

However the last certificate in the ssl checker chain was "COMODO RSA Domain Validation Secure Server CA", issued by "COMODO RSA Certification Authority"

It seems that CloudFront does not hold the certificate for "COMODO RSA Certification Authority" and as such thinks the certificate provided by the origin server is self signed.

This was working for a long time before apparently suddenly stopping. What happened was I had just updated our certificates for the year, but during the import, something was changed in the certificate path for all the previous certificates. They all started referencing "COMODO RSA Certification Authority" whereas before the chain was longer and the root was "AddTrust External CA Root".

Bad certificate path

Because of this, switching back to the older cert did not fix the cloudfront issue.

I had to delete the extra certificate named "COMODO RSA Certification Authority", the one that did not reference AddTrust. After doing this, all my website certificates' paths updated to point back to AddTrust/USERTrust again. Note can also open up the bad root certificate from the path, click "Details" -> "Edit Properties" and then disable it that way. This updated the path immediately. You may also need to delete multiple copies of the certificate, found under "Personal" and "Trusted Root Certificate Authorities"

Good certificate path

Finally I had to re select the certificate in IIS to get it to serve the new certificate chain.

After all this, ssl-checker started displaying a third certificate in the chain, which pointed back to "AddTrust External CA Root"

SSL Checker with all certificates

Finally, CloudFront accepted the origin server's certificate and the provided chain as being trusted. Our CDN started working correctly again!

To prevent this happening in the future, we will need to export our newly generated certificates from a machine with the correct certificate chain, i.e. distrust or delete the certificate "COMODO RSA Certification Authroity" issued by "COMODO RSA Certification Authroity" (expiring in 2038). This only seems to affect windows machines, where this certificate is installed by default.

Check if inputs are empty using jQuery

A clean CSS-only solution this would be:

input[type="radio"]:read-only {
        pointer-events: none;

Check if a column contains text using SQL

Just try below script:

Below code works only if studentid column datatype is varchar


How do I rotate a picture in WinForms

You can easily do it by calling this method :

public static Bitmap RotateImage(Image image, float angle)
    if (image == null)
        throw new ArgumentNullException("image");

    PointF offset = new PointF((float)image.Width / 2, (float)image.Height / 2);

    //create a new empty bitmap to hold rotated image
    Bitmap rotatedBmp = new Bitmap(image.Width, image.Height);
    rotatedBmp.SetResolution(image.HorizontalResolution, image.VerticalResolution);

    //make a graphics object from the empty bitmap
    Graphics g = Graphics.FromImage(rotatedBmp);

    //Put the rotation point in the center of the image
    g.TranslateTransform(offset.X, offset.Y);

    //rotate the image

    //move the image back
    g.TranslateTransform(-offset.X, -offset.Y);

    //draw passed in image onto graphics object
    g.DrawImage(image, new PointF(0, 0));

    return rotatedBmp;

don't forget to add a reference to System.Drawing.dll on your project

Example of this method call :

Image image = new Bitmap("waves.png");
Image newImage = RotateImage(image, 360);

How to grant remote access permissions to mysql server for user?


*.* = DB.TABLE you can restrict user to specific database and specific table.

'root'@'%' you can change root with any user you created and % is to allow all IP. You can restrict it by changing %.168.1.1 etc too.

If that doesn't resolve, then also modify my.cnf or my.ini and comment these lines

bind-address = to #bind-address =
skip-networking to #skip-networking

  • Restart MySQL and repeat above steps again.

Raspberry Pi, I found bind-address configuration under \etc\mysql\mariadb.conf.d\50-server.cnf

SQL Server IN vs. EXISTS Performance

I'd go with EXISTS over IN, see below link:

SQL Server: JOIN vs IN vs EXISTS - the logical difference

There is a common misconception that IN behaves equally to EXISTS or JOIN in terms of returned results. This is simply not true.

IN: Returns true if a specified value matches any value in a subquery or a list.

Exists: Returns true if a subquery contains any rows.

Join: Joins 2 resultsets on the joining column.

Blog credit:

Action Bar's onClick listener for the Home button

Best way to customize Action bar onClickListener is onSupportNavigateUp()

This code will be helpful link for helping code

Timestamp to human readable format

here is kooilnc's answer w/ padded 0's

function getFormattedDate() {
    var date = new Date();

    var month = date.getMonth() + 1;
    var day = date.getDate();
    var hour = date.getHours();
    var min = date.getMinutes();
    var sec = date.getSeconds();

    month = (month < 10 ? "0" : "") + month;
    day = (day < 10 ? "0" : "") + day;
    hour = (hour < 10 ? "0" : "") + hour;
    min = (min < 10 ? "0" : "") + min;
    sec = (sec < 10 ? "0" : "") + sec;

    var str = date.getFullYear() + "-" + month + "-" + day + "_" +  hour + ":" + min + ":" + sec;


    return str;

Selenium Webdriver move mouse to Point

If you are using a RemoteWebDriver, you can cast WebElement into RemoteWebElement. You can then call getCoordinates() on that object to get the coordinates.

        WebElement el = driver.findElementById("elementId");
        Coordinates c = ((RemoteWebElement)el).getCoordinates();

Find the index of a dict within a list, by matching the dict's value

Here's a function that finds the dictionary's index position if it exists.

dicts = [{'id':'1234','name':'Jason'},

def find_index(dicts, key, value):
    class Null: pass
    for i, d in enumerate(dicts):
        if d.get(key, Null) == value:
            return i
        raise ValueError('no dict with the key and value combination found')

print find_index(dicts, 'name', 'Tom')
# 1
find_index(dicts, 'name', 'Ensnare')
# ValueError: no dict with the key and value combination found

How to request Google to re-crawl my website?

There are two options. The first (and better) one is using the Fetch as Google option in Webmaster Tools that Mike Flynn commented about. Here are detailed instructions:

  1. Go to: and log in
  2. If you haven't already, add and verify the site with the "Add a Site" button
  3. Click on the site name for the one you want to manage
  4. Click Crawl -> Fetch as Google
  5. Optional: if you want to do a specific page only, type in the URL
  6. Click Fetch
  7. Click Submit to Index
  8. Select either "URL" or "URL and its direct links"
  9. Click OK and you're done.

With the option above, as long as every page can be reached from some link on the initial page or a page that it links to, Google should recrawl the whole thing. If you want to explicitly tell it a list of pages to crawl on the domain, you can follow the directions to submit a sitemap.

Your second (and generally slower) option is, as seanbreeden pointed out, submitting here:

Update 2019:

  1. Login to - Google Search Console
  2. Add a site and verify it with the available methods.
  3. After verification from the console, click on URL Inspection.
  4. In the Search bar on top, enter your website URL or custom URLs for inspection and enter.
  5. After Inspection, it'll show an option to Request Indexing
  6. Click on it and GoogleBot will add your website in a Queue for crawling.

Is it possible to use global variables in Rust?

It's possible but no heap allocation allowed directly. Heap allocation is performed at runtime. Here are a few examples:

static SOME_INT: i32 = 5;
static SOME_STR: &'static str = "A static string";
static SOME_STRUCT: MyStruct = MyStruct {
    number: 10,
    string: "Some string",
static mut db: Option<sqlite::Connection> = None;

fn main() {
    println!("{}", SOME_INT);
    println!("{}", SOME_STR);
    println!("{}", SOME_STRUCT.number);
    println!("{}", SOME_STRUCT.string);

    unsafe {
        db = Some(open_database());

struct MyStruct {
    number: i32,
    string: &'static str,

Conditionally hide CommandField or ButtonField in Gridview

Hide the Entire GridView Column

If you want to remove the column completely (i.e. not just the button) from the table then use a suitable event handler, e.g. for the OnDataBound event, and then hide the appropriate column on the target GridView. Pick an event that will only fire once for this control, i.e. not OnRowDataBound.


<asp:GridView ID="grdUsers" runat="server" DataSourceID="dsProjectUsers" OnDataBound="grdUsers_DataBound">
        <asp:TemplateField HeaderText="Admin Actions">
            <ItemTemplate><asp:Button ID="btnEdit" runat="server" text="Edit" /></ItemTemplate>
        <asp:BoundField DataField="FirstName" HeaderText="First Name" />
        <asp:BoundField DataField="LastName" HeaderText="Last Name" />
        <asp:BoundField DataField="Telephone" HeaderText="Telephone" />


protected void grdUsers_DataBound(object sender, EventArgs e)
        // in this case hiding the first col if not admin
        if (!User.IsInRole(Constants.Role_Name_Admin))
            grdUsers.Columns[0].Visible = false;
    catch (Exception ex)
        // deal with ex

Default fetch type for one-to-one, many-to-one and one-to-many in Hibernate

I know the answers were correct at the time of asking the question - but since people (like me this minute) still happen to find them wondering why their WildFly 10 was behaving differently, I'd like to give an update for the current Hibernate 5.x version:

In the Hibernate 5.2 User Guide it is stated in chapter 11.2. Applying fetch strategies:

The Hibernate recommendation is to statically mark all associations lazy and to use dynamic fetching strategies for eagerness. This is unfortunately at odds with the JPA specification which defines that all one-to-one and many-to-one associations should be eagerly fetched by default. Hibernate, as a JPA provider, honors that default.

So Hibernate as well behaves like Ashish Agarwal stated above for JPA:

OneToMany: LAZY
ManyToOne: EAGER
ManyToMany: LAZY

(see JPA 2.1 Spec)

Efficiently replace all accented characters in a string?

I made a Prototype Version of this:

String.prototype.strip = function() {
  var translate_re = /[öäüÖÄÜß ]/g;
  var translate = {
    "ä":"a", "ö":"o", "ü":"u",
    "Ä":"A", "Ö":"O", "Ü":"U",
    " ":"_", "ß":"ss"   // probably more to come
    return (this.replace(translate_re, function(match){
        return translate[match];})

Use like:

var teststring = 'ä ö ü Ä Ö Ü ß';

This will will change the String to a_o_u_A_O_U_ss

How can a divider line be added in an Android RecyclerView?

The Right way is to define ItemDecoration for the RecyclerView is as following

public class SimpleDividerItemDecoration extends RecyclerView.ItemDecoration {
    private Drawable mDivider;
    public SimpleDividerItemDecoration(Context context) {
        mDivider = ContextCompat.getDrawable(context, R.drawable.line_divider);
    public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
        int left = parent.getPaddingLeft();
        int right = parent.getWidth() - parent.getPaddingRight();
        int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = parent.getChildAt(i);
            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            int top = child.getBottom() + params.bottomMargin;
            int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);


<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android=""
        android:height="1dp" />
    <solid android:color="@color/dark_gray" />

Finally set it like this

recyclerView.addItemDecoration(new SimpleDividerItemDecoration(this));


As pointed by @Alan Solitar


is depreciated instead of that you can use


How to find the Number of CPU Cores via .NET/C#?

It's rather interesting to see how .NET get this internally to say the least... It's as "simple" as below:

namespace System.Threading
    using System;
    using System.Runtime.CompilerServices;

    internal static class PlatformHelper
        private const int PROCESSOR_COUNT_REFRESH_INTERVAL_MS = 0x7530;
        private static volatile int s_lastProcessorCountRefreshTicks;
        private static volatile int s_processorCount;

        internal static bool IsSingleProcessor
                return (ProcessorCount == 1);

        internal static int ProcessorCount
                int tickCount = Environment.TickCount;
                int num2 = s_processorCount;
                if ((num2 == 0) || ((tickCount - s_lastProcessorCountRefreshTicks) >= 0x7530))
                    s_processorCount = num2 = Environment.ProcessorCount;
                    s_lastProcessorCountRefreshTicks = tickCount;
                return num2;

Subset data to contain only columns whose names match a condition

Try grepl on the names of your data.frame. grepl matches a regular expression to a target and returns TRUE if a match is found and FALSE otherwise. The function is vectorised so you can pass a vector of strings to match and you will get a vector of boolean values returned.


#  Data
df <- data.frame( ABC_1 = runif(3),
            ABC_2 = runif(3),
            XYZ_1 = runif(3),
            XYZ_2 = runif(3) )

#      ABC_1     ABC_2     XYZ_1     XYZ_2
#1 0.3792645 0.3614199 0.9793573 0.7139381
#2 0.1313246 0.9746691 0.7276705 0.0126057
#3 0.7282680 0.6518444 0.9531389 0.9673290

#  Use grepl
df[ , grepl( "ABC" , names( df ) ) ]
#      ABC_1     ABC_2
#1 0.3792645 0.3614199
#2 0.1313246 0.9746691
#3 0.7282680 0.6518444

#  grepl returns logical vector like this which is what we use to subset columns
grepl( "ABC" , names( df ) )

To answer the second part, I'd make the subset data.frame and then make a vector that indexes the rows to keep (a logical vector) like this...

df <- data.frame( ABC_1 = sample(0:1,3,repl = TRUE),
            ABC_2 = sample(0:1,3,repl = TRUE),
            XYZ_1 = sample(0:1,3,repl = TRUE),
            XYZ_2 = sample(0:1,3,repl = TRUE) )

# We will want to discard the second row because 'all' ABC values are 0:
#  ABC_1 ABC_2 XYZ_1 XYZ_2
#1     0     1     1     0
#2     0     0     1     0
#3     1     1     1     0

df1 <- df[ , grepl( "ABC" , names( df ) ) ]

ind <- apply( df1 , 1 , function(x) any( x > 0 ) )

df1[ ind , ]
#  ABC_1 ABC_2
#1     0     1
#3     1     1

Annotation-specified bean name conflicts with existing, non-compatible bean def

I also had a similar problem. I built the project again and the issue was resolved.

The reason is, there are already defined sequences for the Annotation-specified bean names, in a file. When we do a change on that bean name and try to run the application Spring cannot identify which one to pick. That is why it shows this error.

In my case, I removed the previous bean class from the project and added the same bean name to a new bean class. So Spring has the previous definition for the removed bean class in a file and that conflicts with the newly added class while compiling. So if you do a 'build clean', previous definitions for bean classes will be removed and compilation will success.

Truncate (not round) decimal places in SQL Server

I know this question is really old but nobody used sub-strings to round. This as advantage the ability to round really long numbers (limit of your string in SQL server which is usually 8000 characters):

SUBSTRING('123.456', 1, CHARINDEX('.', '123.456') + 2)

Linq : select value in a datatable column

I notice others have given the non-lambda syntax so just to have this complete I'll put in the lambda syntax equivalent:

Non-lambda (as per James's post):

var name = from i in DataContext.MyTable
           where i.ID == 0
           select i.Name

Equivalent lambda syntax:

var name = DataContext.MyTable.Where(i => i.ID == 0)
                              .Select(i => new { Name = i.Name });

There's not really much practical difference, just personal opinion on which you prefer.

Which characters are valid/invalid in a JSON key name?

The following characters must be escaped in JSON data to avoid any problems:

  • " (double quote)
  • \ (backslash)
  • all control characters like \n, \t

JSON Parser can help you to deal with JSON.

Use of "this" keyword in C++

For the example case above, it is usually omitted, yes. However, either way is syntactically correct.

Differences between Lodash and Underscore.js

I am not sure if that is what OP meant, but I came across this question because I was searching for a list of issues I have to keep in mind when migrating from Underscore.js to Lodash.

I would really appreciate if someone posted an article with a complete list of such differences. Let me start with the things I've learned the hard way (that is, things which made my code explode on production:/):

  • _.flatten in Underscore.js is deep by default, and you have to pass true as second argument to make it shallow. In Lodash it is shallow by default and passing true as second argument will make it deep! :)
  • _.last in Underscore.js accepts a second argument which tells how many elements you want. In Lodash there is no such option. You can emulate this with .slice
  • _.first (same issue)
  • _.template in Underscore.js can be used in many ways, one of which is providing the template string and data and getting HTML back (or at least that's how it worked some time ago). In Lodash you receive a function which you should then feed with the data.
  • _(something).map(foo) works in Underscore.js, but in Lodash I had to rewrite it to,foo). Perhaps that was just a TypeScript-issue.

Java 8 stream map to list of keys sorted by values

Map<Integer, String> map = new HashMap<>();
map.put(1, "B");
map.put(2, "C");
map.put(3, "D");
map.put(4, "A");

List<String> list = map.values()

Output: [A, B, C, D]

Is there a command like "watch" or "inotifywait" on the Mac?

watchdog is a cross-platform python API for watching files / directories, and it has builtin "tricks" tool that allows you to trigger actions (including shell commands) when events occur (including new added file, removed file and changed file).

Reversing a linked list in Java, recursively

I think this is more cleaner solution, which resembles LISP

// Example:
// reverse0(1->2->3, null) => 
//      reverse0(2->3, 1) => 
//          reverse0(3, 2->1) => reverse0(null, 3->2->1)
// once the first argument is null, return the second arg
// which is nothing but the reveresed list.

Link reverse0(Link f, Link n) {
    if (f != null) {
        Link t = new Link(f.data1, f.data2); 
        t.nextLink = n;                      
        f = f.nextLink;             // assuming first had n elements before, 
                                    // now it has (n-1) elements
        reverse0(f, t);
    return n;

How do I check if a Sql server string is null or empty

   CASE WHEN LEN(listing.OfferText) > 0 THEN listing.OfferText 
        ELSE COALESCE(Company.OfferText, '') END 
   AS Offer_Text,


In this example, if listing.OfferText is NULL, the LEN() function should also return NULL, but that's still not > 0.


I've learned some things in the 5 1/2 years since posting this, and do it much differently now:

COALESCE(NULLIF(listing.OfferText,''), Company.OfferText, '')

This is similar to the accepted answer, but it also has a fallback in case Company.OfferText is also null. None of the other current answers using NULLIF() also do this.

Uninstall / remove a Homebrew package including all its dependencies

Based on @jfmercer answer (corrections needed more than a comment).

Remove package's dependencies (does not remove package):

brew deps [FORMULA] | xargs brew remove --ignore-dependencies

Remove package:

brew remove [FORMULA]

Reinstall missing libraries:

brew missing | cut -d: -f2 | sort | uniq | xargs brew install

Tested uninstalling meld after discovering MeldMerge releases.

req.query and req.param in ExpressJS

I would suggest using following


req.param("") works as following

Lookup is performed in the following order:


Direct access to req.body, req.params, and req.query should be favoured for clarity - unless you truly accept input from each object.


How to show and update echo on same line

The rest of answers are pretty good, but just wanted to add some extra information in case someone comes here looking for a solution to replace/update a multiline echo.

So I would like to share an example with you all. The following script was tried on a CentOS system and uses "timedatectl" command which basically prints some detailed time information of your system.

I decided to use that command as its output contains multiple lines and works perfectly for the example below:

while true; do
  COMMAND=$(timedatectl) #Save command result in a var.
  echo "$COMMAND" #Print command result, including new lines.

  sleep 3 #Keep above's output on screen during 3 seconds before clearing it

  #Following code clears previously printed lines
  LINES=$(echo "$COMMAND" | wc -l) #Calculate number of lines for the output previously printed
  for (( i=1; i <= $(($LINES)); i++ ));do #For each line printed as a result of "timedatectl"
    tput cuu1 #Move cursor up by one line
    tput el #Clear the line


The above will print the result of "timedatectl" forever and will replace the previous echo with updated results.

I have to mention that this code is only an example, but maybe not the best solution for you depending on your needs. A similar command that would do almost the same (at least visually) is "watch -n 3 timedatectl".

But that's a different story. :)

Hope that helps!

Instagram API to fetch pictures with specific hashtags

Firstly, the Instagram API endpoint "tags" required OAuth authentication.

You can query results for a particular hashtag (snowy in this case) using the following url

It is rate limited to 5000 (X-Ratelimit-Limit:5000) per hour

Sample response

  "pagination":  {
    "next_max_tag_id": "1370433362010",
    "deprecation_warning": "next_max_id and min_id are deprecated for this endpoint; use min_tag_id and max_tag_id instead",
    "next_max_id": "1370433362010",
    "next_min_id": "1370443976800",
    "min_tag_id": "1370443976800",
    "next_url": ""
  "meta":  {
    "code": 200
  "data":  [
      "attribution": null,
      "tags":  [
      "type": "image",
      "location": null,
      "comments":  {
        "count": 0,
        "data":  []
      "filter": null,
      "created_time": "1370418343",
      "link": "",
      "likes":  {
        "count": 1,
        "data":  [
            "username": "iri92lol",
            "profile_picture": "",
            "id": "404174490",
            "full_name": "Iri"
      "images":  {
        "low_resolution":  {
          "url": "",
          "width": 306,
          "height": 306
        "thumbnail":  {
          "url": "",
          "width": 150,
          "height": 150
        "standard_resolution":  {
          "url": "",
          "width": 612,
          "height": 612
      "users_in_photo":  [],
      "caption":  {
        "created_time": "1370418353",
        "text": "#snowy",
        "from":  {
          "username": "iri92lol",
          "profile_picture": "",
          "id": "404174490",
          "full_name": "Iri"
        "id": "471425773832908504"
      "user_has_liked": false,
      "id": "471425689728724453_404174490",
      "user":  {
        "username": "iri92lol",
        "website": "",
        "profile_picture": "",
        "full_name": "Iri",
        "bio": "",
        "id": "404174490"

You can play around here :

You need to use "Authentication" as OAuth 2 and will be prompted to signin via Instagram. Post that you might have to reneter the "tag-name" in "Template" section.

All the pagination related data is available in the "pagination" parameter in the response and use it's "next_url" to query for the next set of result.

How to generate a unique hash code for string input in android...?

For me it worked

   public static long getUniqueLongFromString (String value){
       return  UUID.nameUUIDFromBytes(value.getBytes()).getMostSignificantBits();

Configure hibernate (using JPA) to store Y/N for type Boolean instead of 0/1

This is pure JPA without using getters/setters. As of 2013/2014 it is the best answer without using any Hibernate specific annotations, but please note this solution is JPA 2.1, and was not available when the question was first asked:

public class Person {    

    private Boolean isAlive;    

And then:

public class BooleanToStringConverter implements AttributeConverter<Boolean, String> {

    public String convertToDatabaseColumn(Boolean value) {        
        return (value != null && value) ? "Y" : "N";            

    public Boolean convertToEntityAttribute(String value) {
        return "Y".equals(value);


The implementation above considers anything different from character "Y", including null, as false. Is that correct? Some people here consider this incorrect, and believe that null in the database should be null in Java.

But if you return null in Java, it will give you a NullPointerException if your field is a primitive boolean. In other words, unless some of your fields actually use the class Boolean it's best to consider null as false, and use the above implementation. Then Hibernate will not to emit any exceptions regardless of the contents of the database.

And if you do want to accept null and emit exceptions if the contents of the database are not strictly correct, then I guess you should not accept any characters apart from "Y", "N" and null. Make it consistent, and don't accept any variations like "y", "n", "0" and "1", which will only make your life harder later. This is a more strict implementation:

public String convertToDatabaseColumn(Boolean value) {
    if (value == null) return null;
    else return value ? "Y" : "N";

public Boolean convertToEntityAttribute(String value) {
    if (value == null) return null;
    else if (value.equals("Y")) return true;
    else if (value.equals("N")) return false;
    else throw new IllegalStateException("Invalid boolean character: " + value);

And yet another option, if you want to allow for null in Java but not in the database:

public String convertToDatabaseColumn(Boolean value) {
    if (value == null) return "-";
    else return value ? "Y" : "N";

public Boolean convertToEntityAttribute(String value) {
    if (value.equals("-") return null;
    else if (value.equals("Y")) return true;
    else if (value.equals("N")) return false;
    else throw new IllegalStateException("Invalid boolean character: " + value);

create array from mysql query php

You do need to iterate through...

$typeArray = array();
$query = "select * from whatever";
$result = mysql_query($query);

if ($result) {
    while ($record = mysql_fetch_array($results)) $typeArray[] = $record['type'];

Getting the object's property name

As of 2018 , You can make use of Object.getOwnPropertyNames() as described in Developer Mozilla Documentation

const object1 = {
  a: 1,
  b: 2,
  c: 3

// expected output: Array ["a", "b", "c"]

YouTube Video Embedded via iframe Ignoring z-index?

All you need on the iframe is:


and in the URL:

How do I change file permissions in Ubuntu

So that you don't mess up other permissions already on the file, use the flag +, such as via

sudo chmod -R o+rw /var/www

How can I ping a server port with PHP?

I think the answer to this question pretty much sums up the problem with your question.

If what you want to do is find out whether a given host will accept TCP connections on port 80, you can do this:

$host = ''; 
$port = 80; 
$waitTimeoutInSeconds = 1; 
if($fp = fsockopen($host,$port,$errCode,$errStr,$waitTimeoutInSeconds)){   
   // It worked 
} else {
   // It didn't work 

For anything other than TCP it will be more difficult (although since you specify 80, I guess you are looking for an active HTTP server, so TCP is what you want). TCP is sequenced and acknowledged, so you will implicitly receive a returned packet when a connection is successfully made. Most other transport protocols (commonly UDP, but others as well) do not behave in this manner, and datagrams will not be acknowledged unless the overlayed Application Layer protocol implements it.

The fact that you are asking this question in this manner tells me you have a fundamental gap in your knowledge on Transport Layer protocols. You should read up on ICMP and TCP, as well as the OSI Model.

Also, here's a slightly cleaner version to ping to hosts.

// Function to check response time
function pingDomain($domain){
    $starttime = microtime(true);
    $file      = fsockopen ($domain, 80, $errno, $errstr, 10);
    $stoptime  = microtime(true);
    $status    = 0;

    if (!$file) $status = -1;  // Site is down
    else {
        $status = ($stoptime - $starttime) * 1000;
        $status = floor($status);
    return $status;

Does Notepad++ show all hidden characters?

In newer versions of Notepad++ (currently 5.9), this option is under:

View->Show Symbol->Show All Characters


View->Show Symbol->Show White Space and Tab

OpenCV with Network Cameras

I just do it like this:

CvCapture *capture = cvCreateFileCapture("rtsp://camera-address");

Also make sure this dll is available at runtime else cvCreateFileCapture will return NULL


The camera needs to allow unauthenticated access too, usually set via its web interface. MJPEG format worked via rtsp but MPEG4 didn't.



How to determine equality for two JavaScript objects?

I'd advise against hashing or serialization (as the JSON solution suggest). If you need to test if two objects are equal, then you need to define what equals means. It could be that all data members in both objects match, or it could be that must the memory locations match (meaning both variables reference the same object in memory), or may be that only one data member in each object must match.

Recently I developed an object whose constructor creates a new id (starting from 1 and incrementing by 1) each time an instance is created. This object has an isEqual function that compares that id value with the id value of another object and returns true if they match.

In that case I defined "equal" as meaning the the id values match. Given that each instance has a unique id this could be used to enforce the idea that matching objects also occupy the same memory location. Although that is not necessary.

How to activate a specific worksheet in Excel?

An alternative way to (not dynamically) link a text to activate a worksheet without macros is to make the selected string an actual link. You can do this by selecting the cell that contains the text and press CTRL+K then select the option/tab 'Place in this document' and select the tab you want to activate. If you would click the text (that is now a link) the configured sheet will become active/selected.

Out-File -append in Powershell does not produce a new line and breaks string into characters

Add-Content is default ASCII and add new line however Add-Content brings locked files issues too.

Difference between JSONObject and JSONArray

Best programmatically Understanding.

when syntax is {}then this is JsonObject

when syntax is [] then this is JsonArray

A JSONObject is a JSON-like object that can be represented as an element in the JSONArray. JSONArray can contain a (or many) JSONObject

Hope this will helpful to you !

Function passed as template argument

Came here with the additional requirement, that also parameter/return types should vary. Following Ben Supnik this would be for some type T

typedef T(*binary_T_op)(T, T);

instead of

typedef int(*binary_int_op)(int, int);

The solution here is to put the function type definition and the function template into a surrounding struct template.

template <typename T> struct BinOp
    typedef T(*binary_T_op )(T, T); // signature for all valid template params
    template<binary_T_op op>
    T do_op(T a, T b)
       return op(a,b);

double mulDouble(double a, double b)
    return a * b;

BinOp<double> doubleBinOp;

double res = doubleBinOp.do_op<&mulDouble>(4, 5);

Alternatively BinOp could be a class with static method template do_op(...), then called as

double res = BinOp<double>::do_op<&mulDouble>(4, 5);

How to modify existing XML file with XmlDocument and XmlNode in C#

You need to do something like this:

// instantiate XmlDocument and load XML from file
XmlDocument doc = new XmlDocument();

// get a list of nodes - in this case, I'm selecting all <AID> nodes under
// the <GroupAIDs> node - change to suit your needs
XmlNodeList aNodes = doc.SelectNodes("/Equipment/DataCollections/GroupAIDs/AID");

// loop through all AID nodes
foreach (XmlNode aNode in aNodes)
   // grab the "id" attribute
   XmlAttribute idAttribute = aNode.Attributes["id"];

   // check if that attribute even exists...
   if (idAttribute != null)
      // if yes - read its current value
      string currentValue = idAttribute.Value;

      // here, you can now decide what to do - for demo purposes,
      // I just set the ID value to a fixed value if it was empty before
      if (string.IsNullOrEmpty(currentValue))
         idAttribute.Value = "515";

// save the XmlDocument back to disk

How to set a default value for an existing column

Just Found 3 simple steps to alter already existing column that was null before

update   orders
set BasicHours=0 where BasicHours is null

alter table orders 
add default(0) for BasicHours

alter table orders 
alter  column CleanBasicHours decimal(7,2) not null 

How does one parse XML files?

If you're processing a large amount of data (many megabytes) then you want to be using XmlReader to stream parse the XML.

Anything else (XPathNavigator, XElement, XmlDocument and even XmlSerializer if you keep the full generated object graph) will result in high memory usage and also a very slow load time.

Of course, if you need all the data in memory anyway, then you may not have much choice.

C++ wait for user input

There is no "standard" library function to do this. The standard (perhaps surprisingly) does not actually recognise the concept of a "keyboard", albeit it does have a standard for "console input".

There are various ways to achieve it on different operating systems (see herohuyongtao's solution) but it is not portable across all platforms that support keyboard input.

Remember that C++ (and C) are devised to be languages that can run on embedded systems that do not have keyboards. (Having said that, an embedded system might not have various other devices that the standard library supports).

This matter has been debated for a long time.

R apply function with multiple parameters

Just pass var2 as an extra argument to one of the apply functions.

mylist <- list(a=1,b=2,c=3)
myfxn <- function(var1,var2){
var2 <- 2


This passes the same var2 to every call of myfxn. If instead you want each call of myfxn to get the 1st/2nd/3rd/etc. element of both mylist and var2, then you're in mapply's domain.

How to draw lines in Java

To give you some idea:

public void paint(Graphics g) {

private void drawCoordinates(Graphics g) {

  // get width & height here (w,h)

  // define grid width (dh, dv)

  for (int x = 0; i < w; i += dh) {
    g.drawLine(x, 0, x, h);
  for (int y = 0; j < h; j += dv) {
      g.drawLine(0, y, w, y);

the best way to make codeigniter website multi-language. calling from lang arrays depends on lang session?

you can make a function like this

function translateTo($language, $word) {  
   if (isset($lang[$language][$word]) == FALSE)  
      return $lang[$language][$word];  
      return $lang[defaultLang][$word];  

How to quickly check if folder is empty (.NET)?

Thanks, everybody, for replies. I tried to use Directory.GetFiles() and Directory.GetDirectories() methods. Good news! The performance improved ~twice! 229 calls in 221ms. But also I hope, that it is possible to avoid enumeration of all items in the folder. Agree, that still the unnecessary job is executing. Don't you think so?

After all investigations, I reached a conclusion, that under pure .NET further optimiation is impossible. I am going to play with WinAPI's FindFirstFile function. Hope it will help.

Node Version Manager install - nvm command not found

For MacOS;

Run on Terminal >

open ~/.bash_profile

Paste all of this=

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/" ] && . "$NVM_DIR/" # This loads nvm

long long int vs. long int vs. int64_t in C++

So my question is: Is there a way to tell the compiler that a long long int is the also a int64_t, just like long int is?

This is a good question or problem, but I suspect the answer is NO.

Also, a long int may not be a long long int.

# if __WORDSIZE == 64
typedef long int  int64_t;
# else
typedef long long int  int64_t;
# endif

I believe this is libc. I suspect you want to go deeper.

In both 32-bit compile with GCC (and with 32- and 64-bit MSVC), the output of the program will be:

int:           0
int64_t:       1
long int:      0
long long int: 1

32-bit Linux uses the ILP32 data model. Integers, longs and pointers are 32-bit. The 64-bit type is a long long.

Microsoft documents the ranges at Data Type Ranges. The say the long long is equivalent to __int64.

However, the program resulting from a 64-bit GCC compile will output:

int:           0
int64_t:       1
long int:      1
long long int: 0

64-bit Linux uses the LP64 data model. Longs are 64-bit and long long are 64-bit. As with 32-bit, Microsoft documents the ranges at Data Type Ranges and long long is still __int64.

There's a ILP64 data model where everything is 64-bit. You have to do some extra work to get a definition for your word32 type. Also see papers like 64-Bit Programming Models: Why LP64?

But this is horribly hackish and does not scale well (actual functions of substance, uint64_t, etc)...

Yeah, it gets even better. GCC mixes and matches declarations that are supposed to take 64 bit types, so its easy to get into trouble even though you follow a particular data model. For example, the following causes a compile error and tells you to use -fpermissive:

#if __LP64__
typedef unsigned long word64;
typedef unsigned long long word64;

// intel definition of rdrand64_step (
// extern int _rdrand64_step(unsigned __int64 *random_val);

// Try it:
word64 val;
int res = rdrand64_step(&val);

It results in:

error: invalid conversion from `word64* {aka long unsigned int*}' to `long long unsigned int*'

So, ignore LP64 and change it to:

typedef unsigned long long word64;

Then, wander over to a 64-bit ARM IoT gadget that defines LP64 and use NEON:

error: invalid conversion from `word64* {aka long long unsigned int*}' to `uint64_t*'

What is the purpose of the single underscore "_" variable in Python?

Underscore _ is considered as "I don't Care" or "Throwaway" variable in Python

  • The python interpreter stores the last expression value to the special variable called _.

    >>> 10 
    >>> _ 
    >>> _ * 3 
  • The underscore _ is also used for ignoring the specific values. If you don’t need the specific values or the values are not used, just assign the values to underscore.

    Ignore a value when unpacking

    x, _, y = (1, 2, 3)
    >>> x
    >>> y 

    Ignore the index

    for _ in range(10):     

what is the most efficient way of counting occurrences in pandas?

I think df['word'].value_counts() should serve. By skipping the groupby machinery, you'll save some time. I'm not sure why count should be much slower than max. Both take some time to avoid missing values. (Compare with size.)

In any case, value_counts has been specifically optimized to handle object type, like your words, so I doubt you'll do much better than that.

scp via java

Take a look here

That is the source code for Ants' SCP task. The code in the "execute" method is where the nuts and bolts of it are. This should give you a fair idea of what is required. It uses JSch i believe.

Alternatively you could also directly execute this Ant task from your java code.

Replace first occurrence of string in Python

Use re.sub directly, this allows you to specify a count:

regex.sub('', url, 1)

(Note that the order of arguments is replacement, original not the opposite, as might be suspected.)

Multiline input form field using Bootstrap

The answer by Nick Mitchinson is for Bootstrap version 2.

If you are using Bootstrap version 3, then forms have changed a bit. For bootstrap 3, use the following instead:

<div class="form-horizontal">
    <div class="form-group">
        <div class="col-md-6">
            <textarea class="form-control" rows="3" placeholder="What's up?" required></textarea>

Where, col-md-6 will target medium sized devices. You can add col-xs-6 etc to target smaller devices.

IIS URL Rewrite and Web.config

Just tried this rule, and it worked with GoDaddy hosting since they've already have the Microsoft URL Rewriting module installed for every IIS 7 account.

    <rule name="enquiry" stopProcessing="true">
      <match url="^enquiry$" />
      <action type="Rewrite" url="/Enquiry.aspx" />

How to solve munmap_chunk(): invalid pointer error in C++

This happens when the pointer passed to free() is not valid or has been modified somehow. I don't really know the details here. The bottom line is that the pointer passed to free() must be the same as returned by malloc(), realloc() and their friends. It's not always easy to spot what the problem is for a novice in their own code or even deeper in a library. In my case, it was a simple case of an undefined (uninitialized) pointer related to branching.

The free() function frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc(), calloc() or realloc(). Otherwise, or if free(ptr) has already been called before, undefined behavior occurs. If ptr is NULL, no operation is performed. GNU 2012-05-10 MALLOC(3)

char *words; // setting this to NULL would have prevented the issue

if (condition) {
    words = malloc( 512 );

    /* calling free sometime later works here */

} else {

    /* do not allocate words in this branch */

/* free(words);  -- error here --
*** glibc detected *** ./bin: munmap_chunk(): invalid pointer: 0xb________ ***/

There are many similar questions here about the related free() and rellocate() functions. Some notable answers providing more details:

*** glibc detected *** free(): invalid next size (normal): 0x0a03c978 ***
*** glibc detected *** sendip: free(): invalid next size (normal): 0x09da25e8 ***
glibc detected, realloc(): invalid pointer

IMHO running everything in a debugger (Valgrind) is not the best option because errors like this are often caused by inept or novice programmers. It's more productive to figure out the issue manually and learn how to avoid it in the future.

Form content type for a json HTTP POST?

I have wondered the same thing. Basically it appears that the html spec has different content types for html and form data. Json only has a single content type.

According to the spec, a POST of json data should have the content-type:

Relevant portion of the HTML spec

6.7 Content types (MIME types)
Examples of content types include "text/html", "image/png", "image/gif", "video/mpeg", "text/css", and "audio/basic".

17.13.4 Form content types
This is the default content type. Forms submitted with this content type must be encoded as follows

Relevant portion of the JSON spec

  1. IANA Considerations
    The MIME media type for JSON text is application/json.

What is the default font of Sublime Text?

The default font on windows 10 is Consolas

Git - how delete file from remote repository

If you deleted a file from the working tree, then commit the deletion:

git commit -a -m "A file was deleted"

And push your commit upstream:

git push

Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)

Not sure if anyone is having the same responsive issue, but it was just a simple css solution for me.

same example

...  ng-init="isCollapsed = true" ng-click="isCollapsed = !isCollapsed"> ...
...  div collapse="isCollapsed"> ...


@media screen and (min-width: 768px) {
        display: block !important;

how to make a jquery "$.post" request synchronous

jQuery < 1.8

May I suggest that you use $.ajax() instead of $.post() as it's much more customizable.

If you are calling $.post(), e.g., like this:

$.post( url, data, success, dataType );

You could turn it into its $.ajax() equivalent:

  type: 'POST',
  url: url,
  data: data,
  success: success,
  dataType: dataType,

Please note the async:false at the end of the $.ajax() parameter object.

Here you have a full detail of the $.ajax() parameters: jQuery.ajax() – jQuery API Documentation.

jQuery >=1.8 "async:false" deprecation notice

jQuery >=1.8 won't block the UI during the http request, so we have to use a workaround to stop user interaction as long as the request is processed. For example:

  • use a plugin e.g. BlockUI;
  • manually add an overlay before calling $.ajax(), and then remove it when the AJAX .done() callback is called.

Please have a look at this answer for an example.

Running .sh scripts in Git Bash

If by any chance you've changed the default open for .sh files to a text editor like I had, you can just "bash .\", provided you have git bash installed and in path.

Select from one table matching criteria in another?

select, a.object
from table_A a
inner join table_B b on
where b.tag = 'chair';

How to close jQuery Dialog within the dialog?

replace one string to


$(this) here means another object $("#btnDone")

 <script type="text/javascript">
    $(document).ready(function () {
            autoOpen: true,
            modal: true,
            width: 200,
            draggable: true,
            resizable: true

<div id="form-dialog" title="Form Submit">
<form action="default.aspx" method="post">
<input type="text" name="name" value=" " />    
<input type="submit" value="submit" />

<a href="#" id="btnDone">CLOSE</a>

<script type="text/javascript">
$(document).ready(function () {
    $("#btnDone").click(function () {
 //I've replaced next string
 // $(this) here means another object $("#btnDone")


How do I find duplicates across multiple columns?

You have to self join stuff and match name and city. Then group by count.

from stuff s join stuff p ON ( = OR =
group by having count( > 1

Javascript - removing undefined fields from an object

Mhh.. I think @Damian asks for remove undefined field (property) from an JS object. Then, I would simply do :

for (const i in myObj)  
   if (typeof myObj[i] === 'undefined')   
     delete myObj[i]; 

Short and efficient solution, in (vanilla) JS ! Example :

const myObj = {_x000D_
  a: 1,_x000D_
  b: undefined,_x000D_
  c: null, _x000D_
  d: 'hello world'_x000D_
for (const i in myObj)  _x000D_
  if (typeof myObj[i] === 'undefined')   _x000D_
    delete myObj[i]; _x000D_

Why do multiple-table joins produce duplicate rows?

If one of the tables M, S, D, or H has more than one row for a given Id (if just the Id column is not the Primary Key), then the query would result in "duplicate" rows. If you have more than one row for an Id in a table, then the other columns, which would uniquely identify a row, also must be included in the JOIN condition(s).


Related Question on MSDN Forum

Visual Studio 2017 - Git failed with a fatal error

I got the following error messages using Visual Studio 2017 CE.

Failed to push to the remote repository. See the Output window for more details.

The output window showed the following:

Error encountered while pushing to the remote repository: Git process failed unexpectedly. PushCommand.ExecutePushCommand

I tried to push changes using GitHub Desktop. It shows the following error message.

Cannot push these commits as they contain an email address marked as private on GitHub.

That's It. Solution:

open GitHub account >> Settings >> Emails >> Uncheck "Keep my email address private"

It's done. That was the problem in my case.

"The system cannot find the file C:\ProgramData\Oracle\Java\javapath\java.exe"

Updating the PATH Environment Variable

If you do not set the PATH variable, you need to specify the full path to the executable file every time you run it, such as:

C:\> "C:\Program Files\Java\jdk1.8.0\bin\javac"

It is useful to set the PATH variable permanently so it will persist after rebooting.
To set the PATH variable permanently, add the full path of the jdk1.8.0\bin directory to the PATH variable. Typically, this full path looks something like
C:\Program Files\Java\jdk1.8.0\bin.
Set the PATH variable as follows on Microsoft Windows:

  • Click Start, then Control Panel, then System.
  • Click Advanced, then Environment Variables.
  • Add the location of the bin folder of the JDK installation to the PATH variable in System Variables.
    The following is a typical value for the PATH variable:

    C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files\Java\jdk1.8.0\bin


  • The PATH environment variable is a series of directories separated by semicolons (;) and is not case-sensitive. Microsoft Windows looks for programs in the PATH directories in order, from left to right.

  • You should only have one bin directory for a JDK in the path at a time. Those following the first instance are ignored.

  • If you are not sure where to add the JDK path, append it.

The new path takes effect in each new command window you open after setting the PATH variable.

Passing parameters on button action:@selector

tl;dr: Use Blocks

For Obj-C, for example, there's a CocoaPod SHControlBlocks, whose usage would be:

[self.btnFirst SH_addControlEvents:UIControlEventTouchDown withBlock:^(UIControl *sender) {
    [weakSelf performSegueWithIdentifier:@"second" sender:nil];

For Swift, I love the pod Actions, which allows blocks for UIControls [1]:

// UIControl
let button = UIButton()
button.add(event: .touchUpInside) {
    print("Button tapped")
    playMusic(from: speakers_mp4, withSongAtPosition: indexPath.row)

Not that anyone is reading a 3-year old thread. ::crickets::

[1] And UIView, UITextField, UIGestureRecognizer, UIBarButtonItem, Timer (formally NSTimer), and NotificationCenter (formally NSNotificationCenter).

Get value of a specific object property in C# without knowing the class behind

Use reflection

System.Reflection.PropertyInfo pi = item.GetType().GetProperty("name");
String name = (String)(pi.GetValue(item, null));

SQL Error: ORA-12899: value too large for column

ORA-12899: value too large for column "DJ"."CUSTOMERS"."ADDRESS" (actual: 25, maximum: 2

Tells you what the error is. Address can hold maximum of 20 characters, you are passing 25 characters.

Abstract methods in Python

Before abc was introduced you would see this frequently.

class Base(object):
    def go(self):
        raise NotImplementedError("Please Implement this method")

class Specialized(Base):
    def go(self):
        print "Consider me implemented"

How to copy static files to build directory with Webpack?

The webpack config file (in webpack 2) allows you to export a promise chain, so long as the last step returns a webpack config object. See promise configuration docs. From there:

webpack now supports returning a Promise from the configuration file. This allows to do async processing in you configuration file.

You could create a simple recursive copy function that copies your file, and only after that triggers webpack. E.g.:

module.exports = function(){
    return copyTheFiles( inpath, outpath).then( result => {
        return { entry: "..." } // Etc etc
    } )

Split a string by a delimiter in python

When you have two or more (in the example below there're three) elements in the string, then you can use comma to separate these items:

date, time, event_name = ev.get_text(separator='@').split("@")

After this line of code, the three variables will have values from three parts of the variable ev

So, if the variable ev contains this string and we apply separator '@':

Sa., 23. März@19:00@Klavier + Orchester: SPEZIAL

Then, after split operation the variable

  • date will have value "Sa., 23. März"
  • time will have value "19:00"
  • event_name will have value "Klavier + Orchester: SPEZIAL"

Xcode - Warning: Implicit declaration of function is invalid in C99

The compiler wants to know the function before it can use it

just declare the function before you call it

#include <stdio.h>

int Fibonacci(int number); //now the compiler knows, what the signature looks like. this is all it needs for now

int main(int argc, const char * argv[])
    int input;
    printf("Please give me a number : ");
    scanf("%d", &input);
    printf("The fibonacci number of %d is : %d", input, Fibonacci(input)); //!!!

}/* main */

int Fibonacci(int number)

Font Awesome not working, icons showing as squares

So many answers so I add my working for me (Change name if you dont use PRO): In _typography.less

//  Common
//  _____________________________________________

& when (@media-common = true) {
    @family-name: @font-family-name__fontawsomeregular,
    @font-path: '@{baseDir}fonts/webfonts/fa-regular-400',
    @font-weight: 400,
    @font-style: normal
    @family-name: @font-family-name__fontawsomelight,
    @font-path: '@{baseDir}fonts/webfonts/fa-light-300',
    @font-weight: 300,
    @font-style: normal
    @family-name: @font-family-name__fontawsomebrands,
    @font-path: '@{baseDir}fonts/webfonts/fa-brands-400',
    @font-weight: normal,
    @font-style: normal
    @family-name: @font-family-name__fontawsomesolid,
    @font-path: '@{baseDir}fonts/webfonts/fa-solid-900',
    @font-weight: 900,
    @font-style: normal

In _theme.less

@import '../includes/fontawesome/fontawesome.less';
@fa-font-path: '@{baseDir}fonts/webfonts';

//  Fonts
@font-family-name__fontawsomeregular: 'Font Awesome 5 Pro';
@font-family-name__fontawsomelight: 'Font Awesome 5 Pro';
@font-family-name__fontawsomebrands: 'Font Awesome 5 Brands';
@font-family-name__fontawsomesolid: 'Font Awesome 5 Pro';

and example of usage:

     content: '\f002';
     display: inline-block;
     float: left;
     font-family:  @font-family-name__fontawsomelight;
     font-size: 16px;

How to access the contents of a vector from a pointer to the vector in C++?

The easiest way use it as array is use vector::data() member.

Observable.of is not a function

In rxjs v6, of operator should be imported as import { of } from 'rxjs';

How to: Create trigger for auto update modified date with SQL Server 2008

My approach:

  • define a default constraint on the ModDate column with a value of GETDATE() - this handles the INSERT case

  • have a AFTER UPDATE trigger to update the ModDate column

Something like:

CREATE TRIGGER trg_UpdateTimeEntry
ON dbo.TimeEntry
    UPDATE dbo.TimeEntry
    SET ModDate = GETDATE()

How do I install a plugin for vim?

To expand on Karl's reply, Vim looks in a specific set of directories for its runtime files. You can see that set of directories via :set runtimepath?. In order to tell Vim to also look inside ~/.vim/vim-haml you'll want to add

set runtimepath+=$HOME/.vim/vim-haml

to your ~/.vimrc. You'll likely also want the following in your ~/.vimrc to enable all the functionality provided by vim-haml.

filetype plugin indent on
syntax on

You can refer to the 'runtimepath' and :filetype help topics in Vim for more information.

How should a model be structured in MVC?

More oftenly most of the applications will have data,display and processing part and we just put all those in the letters M,V and C.

Model(M)-->Has the attributes that holds state of application and it dont know any thing about V and C.

View(V)-->Has displaying format for the application and and only knows about how-to-digest model on it and does not bother about C.

Controller(C)---->Has processing part of application and acts as wiring between M and V and it depends on both M,V unlike M and V.

Altogether there is separation of concern between each. In future any change or enhancements can be added very easily.

When are static variables initialized?

The order of initialization is:

  1. Static initialization blocks
  2. Instance initialization blocks
  3. Constructors

The details of the process are explained in the JVM specification document.

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

This is a single loop approach with a hash table for counting the elements and filter the array if the count is 2, because it returns the first found duplicate.


  • single loop
  • uses an object for counting in a closure

var array = [5, 0, 2, 1, 2, 3, 3, 4, 4, 8, 6, 7, 9, 4],_x000D_
    duplicates = array.filter((h => v => (h[v] = (h[v] || 0) + 1) === 2)({}));_x000D_

How to remove any URL within a string in Python

This solution caters for http, https and the other normal url type special characters :

import re
def remove_urls (vTEXT):
    vTEXT = re.sub(r'(https|http)?:\/\/(\w|\.|\/|\?|\=|\&|\%)*\b', '', vTEXT, flags=re.MULTILINE)

print( remove_urls("this is a test lets see this too end"))

Android DialogFragment vs Dialog

You can create generic DialogFragment subclasses like YesNoDialog and OkDialog, and pass in title and message if you use dialogs a lot in your app.

public class YesNoDialog extends DialogFragment
    public static final String ARG_TITLE = "YesNoDialog.Title";
    public static final String ARG_MESSAGE = "YesNoDialog.Message";

    public YesNoDialog()


    public Dialog onCreateDialog(Bundle savedInstanceState)
        Bundle args = getArguments();
        String title = args.getString(ARG_TITLE);
        String message = args.getString(ARG_MESSAGE);

        return new AlertDialog.Builder(getActivity())
            .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener()
                public void onClick(DialogInterface dialog, int which)
                    getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_OK, null);
            .setNegativeButton(, new DialogInterface.OnClickListener()
                public void onClick(DialogInterface dialog, int which)
                    getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_CANCELED, null);

Then call it using the following:

    DialogFragment dialog = new YesNoDialog();
    Bundle args = new Bundle();
    args.putString(YesNoDialog.ARG_TITLE, title);
    args.putString(YesNoDialog.ARG_MESSAGE, message);
    dialog.setTargetFragment(this, YES_NO_CALL);, "tag");

And handle the result in onActivityResult.

javascript cell number validation

If number is your form element, then its length will be undefined since elements don't have length. You want

if (number.value.length != 10) { ... }

An easier way to do all the validation at once, though, would be with a regex:

var val = number.value
if (/^\d{10}$/.test(val)) {
    // value is ok, use it
} else {
    alert("Invalid number; must be ten digits")
    return false

\d means "digit," and {10} means "ten times." The ^ and $ anchor it to the start and end, so something like asdf1234567890asdf does not match.

How to disable clicking inside div

If you want it in pure CSS:


Setting dropdownlist selecteditem programmatically

On load of My Windows Form the comboBox will display the ClassName column of my DataTable as it's the DisplayMember also has its ValueMember (not visible to user) with it.

private void Form1_Load(object sender, EventArgs e)
                this.comboBoxSubjectCName.DataSource = this.Student.TableClass;
                this.comboBoxSubjectCName.DisplayMember = TableColumn.ClassName;//Column name that will be the DisplayMember
                this.comboBoxSubjectCName.ValueMember = TableColumn.ClassID;//Column name that will be the ValueMember

How to solve could not create the virtual machine error of Java Virtual Machine Launcher?

I was facing the same issue while i was using "jdk-10.0.1_windows-x64_bin" and eclipse-jee-oxygen-3a-win32-x86_64 on Windows 64 bit Operating System.

But Finally i resolved this issue by changing my jdk to "jdk-8u172-windows-x64", Now its working fine. @Thanks

Why do I have ORA-00904 even when the column is present?

This happened to me when I accidentally defined two entities with the same persistent database table. In one of the tables the column in question did exist, in the other not. When attempting to persist an object (of the type referring to the wrong underlying database table), this error occurred.

How do I find the PublicKeyToken for a particular dll?

Using PowerShell, you can execute this statement:


The output will provide the Version, Culture and PublicKeyToken as shown below:

MyDLL, Version=, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a

Load image with jQuery and append it to the DOM

With jQuery 3.x use something like:

$('<img src="'+ imgPath +'">').on('load', function() {

How to include libraries in Visual Studio 2012?

In code level also, you could add your lib to the project using the compiler directives #pragma.


#pragma comment( lib, "yourLibrary.lib" )

How can I redirect a php page to another php page?

can use this to redirect

echo '<meta http-equiv="refresh" content="1; URL=index.php" />';

the content=1 can be change to different value to increase the delay before redirection

Reason: no suitable image found

In my case ,the keychain is showing the certificate as untrusted ,to solve this problem I have set the trust options of certificate as "Always trust". Setting the certificate to "Always trust" was the main cause of the crash. I was not able to install the application into device. Solved this by setting trust option to "System defaults" instead of "Always trust" .It worked for me.

Merge two json/javascript arrays in to one array

You can use the new js spread operator if using es6:

var json1 = [{id:1, name: 'xxx'}]_x000D_
var json2 = [{id:2, name: 'xyz'}]_x000D_
var finalObj = [...json1, ...json2]_x000D_

Find row in datatable with specific id

Hello just create a simple function that looks as shown below.. That returns all rows where the call parameter entered is valid or true.

 public  DataTable SearchRecords(string Col1, DataTable RecordDT_, int KeyWORD)
        TempTable = RecordDT_;
        DataView DV = new DataView(TempTable);
        DV.RowFilter = string.Format(string.Format("Convert({0},'System.String')",Col1) + " LIKE '{0}'", KeyWORD);
        return DV.ToTable();

and simply call it as shown below;

  DataTable RowsFound=SearchRecords("IdColumn", OriginalTable,5);

where 5 is the ID. Thanks..

When would you use the Builder Pattern?

Below are some reasons arguing for the use of the pattern and example code in Java, but it is an implementation of the Builder Pattern covered by the Gang of Four in Design Patterns. The reasons you would use it in Java are also applicable to other programming languages as well.

As Joshua Bloch states in Effective Java, 2nd Edition:

The builder pattern is a good choice when designing classes whose constructors or static factories would have more than a handful of parameters.

We've all at some point encountered a class with a list of constructors where each addition adds a new option parameter:

Pizza(int size) { ... }        
Pizza(int size, boolean cheese) { ... }    
Pizza(int size, boolean cheese, boolean pepperoni) { ... }    
Pizza(int size, boolean cheese, boolean pepperoni, boolean bacon) { ... }

This is called the Telescoping Constructor Pattern. The problem with this pattern is that once constructors are 4 or 5 parameters long it becomes difficult to remember the required order of the parameters as well as what particular constructor you might want in a given situation.

One alternative you have to the Telescoping Constructor Pattern is the JavaBean Pattern where you call a constructor with the mandatory parameters and then call any optional setters after:

Pizza pizza = new Pizza(12);

The problem here is that because the object is created over several calls it may be in an inconsistent state partway through its construction. This also requires a lot of extra effort to ensure thread safety.

The better alternative is to use the Builder Pattern.

public class Pizza {
  private int size;
  private boolean cheese;
  private boolean pepperoni;
  private boolean bacon;

  public static class Builder {
    private final int size;

    private boolean cheese = false;
    private boolean pepperoni = false;
    private boolean bacon = false;

    public Builder(int size) {
      this.size = size;

    public Builder cheese(boolean value) {
      cheese = value;
      return this;

    public Builder pepperoni(boolean value) {
      pepperoni = value;
      return this;

    public Builder bacon(boolean value) {
      bacon = value;
      return this;

    public Pizza build() {
      return new Pizza(this);

  private Pizza(Builder builder) {
    size = builder.size;
    cheese = builder.cheese;
    pepperoni = builder.pepperoni;
    bacon = builder.bacon;

Note that Pizza is immutable and that parameter values are all in a single location. Because the Builder's setter methods return the Builder object they are able to be chained.

Pizza pizza = new Pizza.Builder(12)

This results in code that is easy to write and very easy to read and understand. In this example, the build method could be modified to check parameters after they have been copied from the builder to the Pizza object and throw an IllegalStateException if an invalid parameter value has been supplied. This pattern is flexible and it is easy to add more parameters to it in the future. It is really only useful if you are going to have more than 4 or 5 parameters for a constructor. That said, it might be worthwhile in the first place if you suspect you may be adding more parameters in the future.

I have borrowed heavily on this topic from the book Effective Java, 2nd Edition by Joshua Bloch. To learn more about this pattern and other effective Java practices I highly recommend it.

C++ terminate called without an active exception

When a thread object goes out of scope and it is in joinable state, the program is terminated. The Standard Committee had two other options for the destructor of a joinable thread. It could quietly join -- but join might never return if the thread is stuck. Or it could detach the thread (a detached thread is not joinable). However, detached threads are very tricky, since they might survive till the end of the program and mess up the release of resources. So if you don't want to terminate your program, make sure you join (or detach) every thread.

How to call a C# function from JavaScript?

You can use a Web Method and Ajax:

<script type="text/javascript">             //Default.aspx
   function DeleteKartItems() {     
         type: "POST",
         url: 'Default.aspx/DeleteItem',
         data: "",
         contentType: "application/json; charset=utf-8",
         dataType: "json",
         success: function (msg) {
         error: function (e) {
             $("#divResult").html("Something Wrong.");

[WebMethod]                                 //Default.aspx.cs
public static void DeleteItem()
    //Your Logic

How to use sudo inside a docker container?

When neither sudo nor apt-get is available in container, you can also jump into running container as root user using command

docker exec -u root -t -i container_id /bin/bash

ImproperlyConfigured: You must either define the environment variable DJANGO_SETTINGS_MODULE or call settings.configure() before accessing settings

In my case it was the use of the call_command module that posed a problem.
I added set DJANGO_SETTINGS_MODULE=mysite.settings but it didn't work.

I finally found it:

add these lines at the top of the script, and the order matters.

import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "mysite.settings")

import django

from import call_command

Truncate with condition

You can simply export the table with a query clause using datapump and import it back with table_exists_action=replace clause. Its will drop and recreate your table and take very less time. Please read about it before implementing.

1030 Got error 28 from storage engine

A simple: $sth->finish(); Would probably save you from worrying about this. Mysql uses the system's tmp space instead of it's own space.

Footnotes for tables in LaTeX

Probably the best solution is to look at the threeparttable/threeparttablex packages.

Unsigned values in C

Assign a int -1 to an unsigned: As -1 does not fit in the range [0...UINT_MAX], multiples of UINT_MAX+1 are added until the answer is in range. Evidently UINT_MAX is pow(2,32)-1 or 429496725 on OP's machine so a has the value of 4294967295.

    unsigned int a = -1;

The "%x", "%u" specifier expects a matching unsigned. Since these do not match, "If a conversion specification is invalid, the behavior is undefined. If any argument is not the correct type for the corresponding conversion specification, the behavior is undefined." C11 § 9. The printf specifier does not change b.

    printf("%x\n", b);  // UB
    printf("%u\n", b);  // UB

The "%d" specifier expects a matching int. Since these do not match, more UB.

    printf("%d\n", a);  // UB

Given undefined behavior, the conclusions are not supported.

both cases, the bytes are the same (ffffffff).

Even with the same bit pattern, different types may have different values. ffffffff as an unsigned has the value of 4294967295. As an int, depending signed integer encoding, it has the value of -1, -2147483647 or TBD. As a float it may be a NAN.

what is unsigned word for?

unsigned stores a whole number in the range [0 ... UINT_MAX]. It never has a negative value. If code needs a non-negative number, use unsigned. If code needs a counting number that may be +, - or 0, use int.

Update: to avoid a compiler warning about assigning a signed int to unsigned, use the below. This is an unsigned 1u being negated - which is well defined as above. The effect is the same as a -1, but conveys to the compiler direct intentions.

unsigned int a = -1u;

How to make a text box have rounded corners?

You could use CSS to do that, but it wouldn't be supported in IE8-. You can use some site like to come up with actual CSS you'd use, which would look something like this (again, depending on how many browsers you're trying to support):

-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;

How do I create a dictionary with keys from a list and values defaulting to (say) zero?

In python version >= 2.7 and in python 3:

d = {el:0 for el in a}

Why am I getting this redefinition of class error?

If you are having issues with templates or you are calling the class from another .cpp file

try using '#pragma once' in your header file.

Copy a variable's value into another

A solution for AngularJS:

$scope.targetObject = angular.copy($scope.sourceObject)

How do I create a Python function with optional arguments?

Try calling it like: obj.some_function( '1', 2, '3', g="foo", h="bar" ). After the required positional arguments, you can specify specific optional arguments by name.

Is it possible to CONTINUE a loop from an exception?

In the construct you have provided, you don't need a CONTINUE. Once the exception is handled, the statement after the END is performed, assuming your EXCEPTION block doesn't terminate the procedure. In other words, it will continue on to the next iteration of the user_rec loop.

You also need to SELECT INTO a variable inside your BEGIN block:

SELECT attr INTO v_attr FROM attribute_table...

Obviously you must declare v_attr as well...

How to view kafka message

Old version includes ( which is convenient since we do not need cltr+c to exit.

For example --broker-list $BROKERIP:$BROKERPORT --topic $TOPIC1 --property print.key=true --property key.separator=":"  --no-wait-at-logend

Calculate time difference in minutes in SQL Server

You can use DATEDIFF(it is a built-in function) and % (for scale calculation) and CONCAT for make result to only one column

select CONCAT('Month: ',MonthDiff,' Days: ' , DayDiff,' Minutes: ',MinuteDiff,' Seconds: ',SecondDiff) as T  from 
(SELECT DATEDIFF(MONTH, '2017-10-15 19:39:47' , '2017-12-31 23:59:59') % 12 as MonthDiff,
        DATEDIFF(DAY, '2017-10-15 19:39:47' , '2017-12-31 23:59:59') % 30 as DayDiff,
        DATEDIFF(HOUR, '2017-10-15 19:39:47' , '2017-12-31 23:59:59') % 24 as HourDiff,
        DATEDIFF(MINUTE, '2017-10-15 19:39:47' , '2017-12-31 23:59:59') % 60 AS MinuteDiff,
        DATEDIFF(SECOND, '2017-10-15 19:39:47' , '2017-12-31 23:59:59') % 60 AS SecondDiff) tbl

python, sort descending dataframe with pandas

from pandas import DataFrame
import pandas as pd

d = {'one':[2,3,1,4,5],

df = DataFrame(d)

test = df.sort_values(['one'], ascending=False)

What is "runtime"?

As per Wikipedia: runtime library/run-time system.

In computer programming, a runtime library is a special program library used by a compiler, to implement functions built into a programming language, during the runtime (execution) of a computer program. This often includes functions for input and output, or for memory management.

A run-time system (also called runtime system or just runtime) is software designed to support the execution of computer programs written in some computer language. The run-time system contains implementations of basic low-level commands and may also implement higher-level commands and may support type checking, debugging, and even code generation and optimization. Some services of the run-time system are accessible to the programmer through an application programming interface, but other services (such as task scheduling and resource management) may be inaccessible.

Re: your edit, "runtime" and "runtime library" are two different names for the same thing.

What does the DOCKER_HOST variable do?

It points to the docker host! I followed these steps:

$ boot2docker start

Waiting for VM and Docker daemon to start...

To connect the Docker client to the Docker daemon, please set:
    export DOCKER_HOST=tcp://

$ export DOCKER_HOST=tcp://

$ docker run ubuntu:14.04 /bin/echo 'Hello world'
Unable to find image 'ubuntu:14.04' locally
Pulling repository ubuntu
9cbaf023786c: Download complete 
511136ea3c5a: Download complete 
97fd97495e49: Download complete 
2dcbbf65536c: Download complete 
6a459d727ebb: Download complete 
8f321fc43180: Download complete 
03db2b23cf03: Download complete 
Hello world


Add column to SQL Server

Add new column to Table

ADD Column1 Datatype



If User wants to make it auto incremented then


Targeting .NET Framework 4.5 via Visual Studio 2010

There are pretty limited scenarios that I can think of where this would be useful, but let's assume you can't get funds to purchase VS2012 or something to that effect. If that's the case and you have Windows 7+ and VS 2010 you may be able to use the following hack I put together which seems to work (but I haven't fully deployed an application using this method yet).

  1. Backup your project file!!!

  2. Download and install the Windows 8 SDK which includes the .NET 4.5 SDK.

  3. Open your project in VS2010.

  4. Create a text file in your project named Compile_4_5_CSharp.targets with the following contents. (Or just download it here - Make sure to remove the ".txt" extension from the file name):

    <Project DefaultTargets="Build"
        <!-- Change the target framework to 4.5 if using the ".NET 4.5" configuration -->
        <PropertyGroup Condition=" '$(Platform)' == '.NET 4.5' ">
            <DefineConstants Condition="'$(DefineConstants)'==''">
            <DefineConstants Condition="'$(DefineConstants)'!='' and '$(DefineConstants)'!='TARGETTING_FX_4_5'">
            <PlatformTarget Condition="'$(PlatformTarget)'!=''"/>
        <!-- Import the standard C# targets -->
        <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
        <!-- Add .NET 4.5 as an available platform -->
           <AvailablePlatforms>$(AvailablePlatforms),.NET 4.5</AvailablePlatforms>
  5. Unload your project (right click -> unload).

  6. Edit the project file (right click -> Edit *.csproj).

  7. Make the following changes in the project file:

    a. Replace the default Microsoft.CSharp.targets with the target file created in step 4

    <!-- Old Import Entry -->
    <!-- <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" /> -->
    <!-- New Import Entry -->
    <Import Project="Compile_4_5_CSharp.targets" />

    b. Change the default platform to .NET 4.5

    <!-- Old default platform entry -->
    <!-- <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform> -->
    <!-- New default platform entry -->
    <Platform Condition=" '$(Platform)' == '' ">.NET 4.5</Platform>

    c. Add AnyCPU platform to allow targeting other frameworks as specified in the project properties. This should be added just before the first <ItemGroup> tag in the file

    <PropertyGroup Condition="'$(Platform)' == 'AnyCPU'">
  8. Save your changes and close the *.csproj file.

  9. Reload your project (right click -> Reload Project).

  10. In the configuration manager (Build -> Configuration Manager) make sure the ".NET 4.5" platform is selected for your project.

  11. Still in the configuration manager, create a new solution platform for ".NET 4.5" (you can base it off "Any CPU") and make sure ".NET 4.5" is selected for the solution.

  12. Build your project and check for errors.

  13. Assuming the build completed you can verify that you are indeed targeting 4.5 by adding a reference to a 4.5 specific class to your source code:

    using System;
    using System.Text;
    namespace testing
        using net45check = System.Reflection.ReflectionContext;
  14. When you compile using the ".NET 4.5" platform the build should succeed. When you compile under the "Any CPU" platform you should get a compiler error:

    Error 6: The type or namespace name 'ReflectionContext' does not exist in
    the namespace 'System.Reflection' (are you missing an assembly reference?)

How to format strings using printf() to get equal length in the output

Additionally, if you want the flexibility of choosing the width, you can choose between one of the following two formats (with or without truncation):

int width = 30;
// No truncation uses %-*s
printf( "%-*s %s\n", width, "Starting initialization...", "Ok." );
// Output is "Starting initialization...     Ok."

// Truncated to the specified width uses %-.*s
printf( "%-.*s %s\n", width, "Starting initialization...", "Ok." );
// Output is "Starting initialization... Ok."

IOError: [Errno 13] Permission denied

I have a really stupid use case for why I got this error. Originally I was printing my data > file.txt

Then I changed my mind, and decided to use open("file.txt", "w") instead. But when I called python, I left > file.txt .....

How to define Typescript Map of key value pair. where key is a number and value is an array of objects

The most simple way is to use Record type Record<number, productDetails >

interface productDetails {
   productId : number , 
   price : number , 
   discount : number

const myVar : Record<number, productDetails> = {
   1: {
       productId : number , 
       price : number , 
       discount : number

Scrolling to element using webdriver?

There is another option to scroll page to required element if element has "id" attribute

If you want to navigate to page and scroll down to element with @id, it can be done automatically by adding #element_id to URL...


Let's say we need to navigate to Selenium Waits documentation and scroll page down to "Implicit Wait" section. We can do


and add code for scrolling...OR use


to navigate to page AND scroll page automatically to element with id="implicit-waits" (<div class="section" id="implicit-waits">...</div>)

How can I do a case insensitive string comparison?

I think you will find more information in this link:

Use the Compare static method on the String class to compare the two strings. Whether the comparison is case-insensitive is determined by the third parameter of one of its overloads. For example:

string lowerCase = "abc";
string upperCase = "AbC";
int caseInsensitiveResult = string.Compare(lowerCase, upperCase,
int caseSensitiveResult = string.Compare(lowerCase,

The caseSensitiveResult value is -1 (indicating that lowerCase is "less than" upperCase) and the caseInsensitiveResult is zero (indicating that lowerCase "equals" upperCase).

What are WSDL, SOAP and REST?

Every time someone mentions SOAP/WSDL, I think of objects and classes defined in xml...

"You use SOAP just the same way that you would any PHP class. However, in this case the class does not exist in the local applications file system, but at a remote site accessed over http." ... "If we think of using a SOAP service as just another PHP class then the WSDL document is a list of all the available class methods and properties. "

..and whenever someone talks about REST I think of HTTP's commands (request methods) like POST, GET and DELETE

How to find the installed pandas version


pip freeze

It works the same as above.

pip show pandas

Displays information about a specific package. For more information, check out pip help

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

As per

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

you will want to add an application manifest if you don't already have one or don't know how to add one. As some projects don't automatically add a separate manifest file, first go to project properties, navigate to the Application tab and check to make sure your project is not excluding the manifest at the bottom of the tap.

  • Next, right click project
  • Add new Item
  • Last, find and click Application Manifest File

How to check the Angular version?

check the Command Prompt

ng --version OR ng version OR ng -v

How to get default gateway in Mac OSX

I would use something along these lines...

 netstat -rn | grep "default" | awk '{print $2}'

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


basename "$PWD"


echo ${var[-1]} 

Turn the Internal Filename Separator (IFS) back to space.


There is one space after the IFS.

Can't find the 'libpq-fe.h header when trying to install pg gem

I found this answer, and it was the only one that worked for me (Mac OS) - after researching for about two days:

$ sudo su

$ env ARCHFLAGS="-arch x86_64" gem install pg

Building native extensions.  This could take a while...
Successfully installed pg-0.11.0
1 gem installed
Installing ri documentation for pg-0.11.0...
Installing RDoc documentation for pg-0.11.0...

See Stack Overflow question Can't find the PostgreSQL client library (libpq).

animating addClass/removeClass with jQuery

You could use jquery ui's switchClass, Heres an example:

$( "selector" ).switchClass( "oldClass", "newClass", 1000, "easeInOutQuad" );

Or see this jsfiddle.

Any way to exit bash script, but not quitting the terminal

Actually, I think you might be confused by how you should run a script.

If you use sh to run a script, say, sh ./, even if the embedded script ends with exit, your terminal window will still remain.

However if you use . or source, your terminal window will exit/close as well when subscript ends.

for more detail, please refer to What is the difference between using sh and source?

Process.start: how to get the output?

The solution that worked for me in win and linux is the folling

// GET api/values
        public ActionResult<IEnumerable<string>> Cifrado(String xml)
            String nombreXML = DateTime.Now.ToString("ddMMyyyyhhmmss").ToString();
            String archivo = "/app/files/"+nombreXML + ".XML";
            String comando = " --armor --recipient [email protected]  --encrypt " + archivo;
                System.IO.File.WriteAllText(archivo, xml);                
                //String comando = "C:\\GnuPG\\bin\\gpg.exe --recipient [email protected] --armor --encrypt C:\\Users\\Administrador\\Documents\\pruebas\\nuevo.xml ";
                ProcessStartInfo startInfo = new ProcessStartInfo() {FileName = "/usr/bin/gpg",  Arguments = comando }; 
                Process proc = new Process() { StartInfo = startInfo, };
                proc.StartInfo.RedirectStandardOutput = true;
                proc.StartInfo.RedirectStandardError = true;
                return new string[] { "Archivo encriptado", archivo + " - "+ comando};
            }catch (Exception exception){
                return new string[] { archivo, "exception: "+exception.ToString() + " - "+ comando };

Exception of type 'System.OutOfMemoryException' was thrown.

Running in Debug Mode

When you're developing and debugging an application, you will typically run with the debug attribute in the web.config file set to true and your DLLs compiled in debug mode. However, before you deploy your application to test or to production, you should compile your components in release mode and set the debug attribute to false.

ASP.NET works differently on many levels when running in debug mode. In fact, when you are running in debug mode, the GC will allow your objects to remain alive longer (until the end of the scope) so you will always see higher memory usage when running in debug mode.

Another often unrealized side-effect of running in debug mode is that client scripts served via the webresource.axd and scriptresource.axd handlers will not be cached. That means that each client request will have to download any scripts (such as ASP.NET AJAX scripts) instead of taking advantage of client-side caching. This can lead to a substantial performance hit.


Setting an HTML text input box's "default" value. Revert the value when clicking ESC

If the question is: "Is it possible to add value on ESC" than the answer is yes. You can do something like that. For example with use of jQuery it would look like below.


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

<input type="text" value="default!" id="myInput" />


$(document).ready(function (){
    $('#myInput').keyup(function(event) {
        // 27 is key code of ESC
        if (event.keyCode == 27) {
            // Loose focus on input field

Working source can be found here:

Please let me know if you meant something different, I can adjust the code later.

Angular HTTP GET with TypeScript error http.get(...).map is not a function in [null]

import { map } from 'rxjs/operators';

this works for me in angular 8

POST JSON to API using Rails and HTTParty

The :query_string_normalizer option is also available, which will override the default normalizer HashConversions.to_params(query)

query_string_normalizer: ->(query){query.to_json}

What causes the error "_pickle.UnpicklingError: invalid load key, ' '."?

I had a similar error but with different context when I uploaded a *.p file to Google Drive. I tried to use it later in a Google Colab session, and got this error:

    1 with open("/tmp/train.p", mode='rb') as training_data:
----> 2     train = pickle.load(training_data)
UnpicklingError: invalid load key, '<'.

I solved it by compressing the file, upload it and then unzip on the session. It looks like the pickle file is not saved correctly when you upload/download it so it gets corrupted.

Comments in Android Layout xml

you can also add comment by pressing Ctrl+shift+/ and shift+ / for one line.

Reading a resource file from within jar

You can use class loader which will read from classpath as ROOT path (without "/" in the beginning)

InputStream in = getClass().getClassLoader().getResourceAsStream("file.txt"); 
BufferedReader reader = new BufferedReader(new InputStreamReader(in));

Java: Finding the highest value in an array

You can write like this.

import java.util.Scanner;
class   BigNoArray{

    public static void main(String[] args){
        Scanner sc = new Scanner(;
        System.out.println("Enter how many array element");
        int n=sc.nextInt();
        int[] ar= new int[n];
        System.out.println("enter "+n+" values");
        for(int i=0;i<ar.length;i++){
        int fbig=ar[0];
        int sbig=ar[1];
        int tbig=ar[3];
            for(int i=1;i<ar.length;i++){
                else if(sbig<ar[i]&&ar[i]!=fbig){
                else if(tbig<ar[i]&&ar[i]!=fbig){
        System.out.println("first big number is "+fbig);
        System.out.println("second big number is "+sbig);
        System.out.println("third big number is "+tbig);

ojdbc14.jar vs. ojdbc6.jar

I have same problem!

Found following in oracle site link text

As mentioned above, the 11.1 drivers by default convert SQL DATE to Timestamp when reading from the database. This always was the right thing to do and the change in 9i was a mistake. The 11.1 drivers have reverted to the correct behavior. Even if you didn't set V8Compatible in your application you shouldn't see any difference in behavior in most cases. You may notice a difference if you use getObject to read a DATE column. The result will be a Timestamp rather than a Date. Since Timestamp is a subclass of Date this generally isn't a problem. Where you might notice a difference is if you relied on the conversion from DATE to Date to truncate the time component or if you do toString on the value. Otherwise the change should be transparent.

If for some reason your app is very sensitive to this change and you simply must have the 9i-10g behavior, there is a connection property you can set. Set mapDateToTimestamp to false and the driver will revert to the default 9i-10g behavior and map DATE to Date.

How do you reverse a string in place in JavaScript?

var str = "my name is saurabh ";
var empStr='',finalString='';
var chunk=[];
function reverse(str){
var i,j=0,n=str.length;
        if(str[i]===' '){
            empStr = '';
    for(var z=chunk.length-1;z>=0;z--){
        finalString = finalString +' '+ chunk[z];
    return true;

How to use a link to call JavaScript?

just use javascript:---- exemplale

javascript:var JFL_81371678974472 = new JotformFeedback({ formId: '81371678974472', base: '', windowTitle: 'Photobook Series', background: '#e44c2a', fontColor: '#FFFFFF', type: 'false', height: 700, width: 500, openOnLoad: true })

How do I use .toLocaleTimeString() without displaying seconds?

I wanted it with date and the time but no seconds so I used this:

var dateWithoutSecond = new Date();
dateWithoutSecond.toLocaleTimeString([], {year: 'numeric', month: 'numeric', day: 'numeric', hour: '2-digit', minute: '2-digit'});

It produced the following output:

7/29/2020, 2:46 PM

Which was the exact thing I needed. Worked in FireFox.

Quick way to create a list of values in C#?

If you want to create a typed list with values, here's the syntax.

Assuming a class of Student like

public class Student {
   public int StudentID { get; set; }
   public string StudentName { get; set; }

You can make a list like this:

IList<Student> studentList = new List<Student>() { 
                new Student(){ StudentID=1, StudentName="Bill"},
                new Student(){ StudentID=2, StudentName="Steve"},
                new Student(){ StudentID=3, StudentName="Ram"},
                new Student(){ StudentID=1, StudentName="Moin"}

How to quickly and conveniently create a one element arraylist

The other answers all use Arrays.asList(), which returns an unmodifiable list (an UnsupportedOperationException is thrown if you try to add or remove an element). To get a mutable list you can wrap the returned list in a new ArrayList as a couple of answers point out, but a cleaner solution is to use Guava's Lists.newArrayList() (available since at least Guava 10, released in 2011).

For example:


Merge two (or more) lists into one, in C# .NET

You can use the LINQ Concat and ToList methods:

var allProducts = productCollection1.Concat(productCollection2)

Note that there are more efficient ways to do this - the above will basically loop through all the entries, creating a dynamically sized buffer. As you can predict the size to start with, you don't need this dynamic sizing... so you could use:

var allProducts = new List<Product>(productCollection1.Count +
                                    productCollection2.Count +

(AddRange is special-cased for ICollection<T> for efficiency.)

I wouldn't take this approach unless you really have to though.

Is it possible to ignore one single specific line with Pylint?

Checkout the files in I haven't found a better way to obtain the error name from a message than either Ctrl + F-ing those files or using the GitHub search feature:

If the message is "No name ... in module ...", use the search:

No name %r in module %r repo:PyCQA/pylint/tree/master path:/pylint/checkers

Or, to get fewer results:

"No name %r in module %r" repo:PyCQA/pylint/tree/master path:/pylint/checkers

GitHub will show you:

"E0611": (
    "No name %r in module %r",
    "Used when a name cannot be found in a module.",

You can then do:

from collections import Sequence # pylint: disable=no-name-in-module

Submit form without page reloading

A further possibility is to make a direct javascript link to your function:

<form action="javascript:your_function();" method="post">


How do I set up curl to permanently use a proxy?

You can make a alias in your ~/.bashrc file :

alias curl="curl -x <proxy_host>:<proxy_port>"

Another solution is to use (maybe the better solution) the ~/.curlrc file (create it if it does not exist) :

proxy = <proxy_host>:<proxy_port>

NSRange to Range<String.Index>

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {

       let strString = ((textField.text)! as NSString).stringByReplacingCharactersInRange(range, withString: string)


Removing Duplicate Values from ArrayList

if you want to use only arraylist then I am worried there is no better way which will create a huge performance benefit. But by only using arraylist i would check before adding into the list like following

void addToList(String s){

In this cases using a Set is suitable.

Why does JavaScript only work after opening developer tools in IE once?

If you are using AngularJS version 1.X you could use the $log service instead of using console.log directly.

Simple service for logging. Default implementation safely writes the message into the browser's console (if present).$log

So if you have something similar to

angular.module('logExample', [])
  .controller('LogController', ['$scope', function($scope) {
    console.log('Hello World!');

you can replace it with

angular.module('logExample', [])
  .controller('LogController', ['$scope', '$log', function($scope, $log) {
    $log.log('Hello World!');

Angular 2+ does not have any built-in log service.

Count the number of commits on a Git branch

You can use this command which uses awk on git bash/unix to get the number of commits.

    git shortlog -s -n | awk '/Author/ { print $1 }'

Concat a string to SELECT * MySql

You cannot do this on multiple fields. You can also look for this.

Can I force pip to reinstall the current version?

If you want to reinstall packages specified in a requirements.txt file, without upgrading, so just reinstall the specific versions specified in the requirements.txt file:

pip install -r requirements.txt --ignore-installed

How can I extract the folder path from file path in Python?

The built-in submodule os.path has a function for that very task.

import os

Replace comma with newline in sed on MacOS?

The sed on macOS Mojave was released in 2005, so one solution is to install the gnu-sed,

brew install gnu-sed

then use gsed will do as you wish,

gsed 's/,/\n/g' file

If you prefer sed, just sudo sh -c 'echo /usr/local/opt/gnu-sed/libexec/gnubin > /etc/paths.d/brew', which is suggested by brew info gnu-sed. Restart your term, then your sed in command line is gsed.

Multiple modals overlay

Here is some CSS using nth-of-type selectors that seems to work:

.modal:nth-of-type(even) {
    z-index: 1042 !important;
} {
    z-index: 1041 !important;


How to get JS variable to retain value after page refresh?

You will have to use cookie to store the value across page refresh. You can use any one of the many javascript based cookie libraries to simplify the cookie access, like this one

If you want to support only html5 then you can think of Storage api like localStorage/sessionStorage

Ex: using localStorage and cookies library

var mode = getStoredValue('myPageMode');

function buttonClick(mode) {
    mode = mode;
    storeValue('myPageMode', mode);

function storeValue(key, value) {
    if (localStorage) {
        localStorage.setItem(key, value);
    } else {
        $.cookies.set(key, value);

function getStoredValue(key) {
    if (localStorage) {
        return localStorage.getItem(key);
    } else {
        return $.cookies.get(key);

What does a "Cannot find symbol" or "Cannot resolve symbol" error mean?

We got the error in a Java project that is set up as a Gradle multi-project build. It turned out that one of the sub-projects was missing the Gradle Java Library plugin. This prevented the sub-project's class files from being visible to other projects in the build.

After adding the Java library plugin to the sub-project's build.gradle in the following way, the error went away:

plugins {
    id 'java-library'

Pass in an array of Deferreds to $.when()

I want to propose other one with using $.each:

  1. We may to declare ajax function like:

    function ajaxFn(someData) {
        this.someData = someData;
        var that = this;
        return function () {
            var promise = $.Deferred();
                method: "POST",
                url: "url",
                data: that.someData,
                success: function(data) {
                error: function(data) {
            return promise;
  2. Part of code where we creating array of functions with ajax to send:

    var arrayOfFn = [];
    for (var i = 0; i < someDataArray.length; i++) {
        var ajaxFnForArray = new ajaxFn(someDataArray[i]);
  3. And calling functions with sending ajax:

        $.each(arrayOfFn, function(index, value) {
    ).then(function() {

Sanitizing user input before adding it to the DOM in Javascript

You can use this:

function sanitize(string) {
  const map = {
      '&': '&amp;',
      '<': '&lt;',
      '>': '&gt;',
      '"': '&quot;',
      "'": '&#x27;',
      "/": '&#x2F;',
  const reg = /[&<>"'/]/ig;
  return string.replace(reg, (match)=>(map[match]));

Also see OWASP XSS Prevention Cheat Sheet.

assign multiple variables to the same value in Javascript

The original variables you listed can be declared and assigned to the same value in a short line of code using destructuring assignment. The keywords let, const, and var can all be used for this type of assignment.

let [moveUp, moveDown, moveLeft, moveRight, mouseDown, touchDown] = Array(6).fill(false);

JPA or JDBC, how are they different?

Main difference between JPA and JDBC is level of abstraction.

JDBC is a low level standard for interaction with databases. JPA is higher level standard for the same purpose. JPA allows you to use an object model in your application which can make your life much easier. JDBC allows you to do more things with the Database directly, but it requires more attention. Some tasks can not be solved efficiently using JPA, but may be solved more efficiently with JDBC.

How do I create a local database inside of Microsoft SQL Server 2014?

Warning! SQL Server 14 Express, SQL Server Management Studio, and SQL 2014 LocalDB are separate downloads, make sure you actually installed SQL Server and not just the Management Studio! SQL Server 14 express with LocalDB download link

Youtube video about entire process.
Writeup with pictures about installing SQL Server

How to select a local server:

When you are asked to connect to a 'database server' right when you open up SQL Server Management Studio do this:

1) Make sure you have Server Type: Database

2) Make sure you have Authentication: Windows Authentication (no username & password)

3) For the server name field look to the right and select the drop down arrow, click 'browse for more'

4) New window pops up 'Browse for Servers', make sure to pick 'Local Servers' tab and under 'Database Engine' you will have the local server you set up during installation of SQL Server 14

How do I create a local database inside of Microsoft SQL Server 2014?

1) After you have connected to a server, bring up the Object Explorer toolbar under 'View' (Should open by default)

2) Now simply right click on 'Databases' and then 'Create new Database' to be taken through the database creation tools!

What's the difference between integer class and numeric class in R

There are multiple classes that are grouped together as "numeric" classes, the 2 most common of which are double (for double precision floating point numbers) and integer. R will automatically convert between the numeric classes when needed, so for the most part it does not matter to the casual user whether the number 3 is currently stored as an integer or as a double. Most math is done using double precision, so that is often the default storage.

Sometimes you may want to specifically store a vector as integers if you know that they will never be converted to doubles (used as ID values or indexing) since integers require less storage space. But if they are going to be used in any math that will convert them to double, then it will probably be quickest to just store them as doubles to begin with.

Align labels in form next to input


Nowadays you should definitely avoid using fixed widths. You could use flexbox or CSS grid to come up with a responsive solution. See the other answers.

One possible solution:

  • Give the labels display: inline-block;
  • Give them a fixed width
  • Align text to the right

That is:

label {
  display: inline-block;
  width: 140px;
  text-align: right;
<div class="block">
    <label>Simple label</label>
    <input type="text" />
<div class="block">
    <label>Label with more text</label>
    <input type="text" />
<div class="block">
    <input type="text" />


Best way to script remote SSH commands in Batch (Windows)

The -m switch of PuTTY takes a path to a script file as an argument, not a command.


So you have to save your command (command_run) to a plain text file (e.g. c:\path\command.txt) and pass that to PuTTY:

putty.exe -ssh user@host -pw password -m c:\path\command.txt

Though note that you should use Plink (a command-line connection tool from PuTTY suite). It's a console application, so you can redirect its output to a file (what you cannot do with PuTTY).

A command-line syntax is identical, an output redirection added:

plink.exe -ssh user@host -pw password -m c:\path\command.txt > output.txt

See Using the command-line connection tool Plink.

And with Plink, you can actually provide the command directly on its command-line:

plink.exe -ssh user@host -pw password command > output.txt

Similar questions:
Automating running command on Linux from Windows using PuTTY
Executing command in Plink from a batch file

NUnit vs. MbUnit vs. MSTest vs.

I know this is an old thread, but I thought I'd post a vote for xUnit.NET. While most of the other testing frameworks mentioned are all pretty much the same, xUnit.NET has taken a pretty unique, modern, and flexible approach to unit testing. It changes terminology, so you no longer define TestFixtures and specify Facts and Theories about your code, which integrates better with the concept of what a test is from a TDD/BDD perspective.

xUnit.NET is also EXTREMELY extensible. Its FactAttribute and TraitAttribute attribute classes are not sealed, and provide overridable base methods that give you a lot of control over how the methods those attributes decorate should be executed. While xUnit.NET in its default form allows you to write test classes that are similar to NUnit test fixtures with their test methods, you are not confined to this form of unit testing at all. You are free to extend the framework to support BDD-style Concern/Context/Observation specifications, as depicted here.

xUnit.NET also supports fit-style testing directly out of the box with its Theory attribute and corresponding data attributes. Fit input data may be loaded from excel, database, or even a custom data source such as a Word document (by extending the base data attribute.) This allows you to capitalize on a single testing platform for both unit tests and integration tests, which can be huge in reducing product dependencies and required training.

Other approaches to testing may also be implemented with xUnit.NET...the possibilities are pretty limitless. Combined with another very forward looking mocking framework, Moq, the two create a very flexible, extensible, and powerful platform for implementing automated testing.

.gitignore all the .DS_Store files in every folder and subfolder

You should add following lines while creating a project. It will always ignore .DS_Store to be pushed to the repository.

*.DS_Store this will ignore .DS_Store while code commit.
git rm --cached .DS_Store this is to remove .DS_Store files from your repository, in case you need it, you can uncomment it.

## ignore .DS_Store file.
# git rm --cached .DS_Store

How to default to other directory instead of home directory

Add the line to the .bashrc file in the home directory (create the file if it doesn't exist):

cd ~
touch .bashrc
echo "cd ~/Desktop/repos/" >> .bashrc

How to get the current time in milliseconds in C Programming

If you're on a Unix-like system, use gettimeofday and convert the result from microseconds to milliseconds.

Matplotlib scatter plot with different text at each data point

In case anyone is trying to apply the above solutions to a .scatter() instead of a .subplot(),

I tried running the following code

y = [2.56422, 3.77284, 3.52623, 3.51468, 3.02199]
z = [0.15, 0.3, 0.45, 0.6, 0.75]
n = [58, 651, 393, 203, 123]

fig, ax = plt.scatter(z, y)

for i, txt in enumerate(n):
    ax.annotate(txt, (z[i], y[i]))

But ran into errors stating "cannot unpack non-iterable PathCollection object", with the error specifically pointing at codeline fig, ax = plt.scatter(z, y)

I eventually solved the error using the following code

plt.scatter(z, y)

for i, txt in enumerate(n):
    plt.annotate(txt, (z[i], y[i]))

I didn't expect there to be a difference between .scatter() and .subplot() I should have known better.

Generate random numbers uniformly over an entire range

@Solution ((double) rand() / (RAND_MAX+1)) * (max-min+1) + min

Warning: Don't forget due to stretching and possible precision errors (even if RAND_MAX were large enough), you'll only be able to generate evenly distributed "bins" and not all numbers in [min,max].

@Solution: Bigrand

Warning: Note that this doubles the bits, but still won't be able to generate all numbers in your range in general, i.e., it is not necessarily true that BigRand() will generate all numbers between in its range.

Info: Your approach (modulo) is "fine" as long as the range of rand() exceeds your interval range and rand() is "uniform". The error for at most the first max - min numbers is 1/(RAND_MAX +1).

Also, I suggest to switch to the new random packagee in C++11 too, which offers better and more varieties of implementations than rand().

Append to the end of a Char array in C++

If your arrays are character arrays(which seems to be the case), You need a strcat().
Your destination array should have enough space to accommodate the appended data though.

In C++, You are much better off using std::string and then you can use std::string::append()

How can I compile LaTeX in UTF8?

I have success with using the Chrome addon "Sharelatex". This online editor has great compability with most latex files, but it somewhat lacks configuration possibilities.

Iterating over each line of ls -l output

So, why didn't anybody suggest just using options that eliminate the parts he doesn't want to process.

On modern Debian you just get your file with:

ls --format=single-column 

Further more, you don't have to pay attention to what directory you are running it in if you use the full directory:

ls --format=single-column /root/dir/starting/point/to/target/dir/

This last command I am using the above and I get the following output:

bot@dev:~/downloaded/Daily# ls --format=single-column /home/bot/downloaded/Daily/*.gz

Extract a subset of a dataframe based on a condition involving a field

Just to extend the answer above you can also index your columns rather than specifying the column names which can also be useful depending on what you're doing. Given that your location is the first field it would look like this:

    bar <- foo[foo[ ,1] == "there", ]

This is useful because you can perform operations on your column value, like looping over specific columns (and you can do the same by indexing row numbers too).

This is also useful if you need to perform some operation on more than one column because you can then specify a range of columns:

    foo[foo[ ,c(1:N)], ]

Or specific columns, as you would expect.

    foo[foo[ ,c(1,5,9)], ]

How to Implement DOM Data Binding in JavaScript

A simple way of binding a variable to an input (two-way binding) is to just directly access the input element in the getter and setter:

var variable = function(element){                    
                   return {
                       get : function () { return element.value;},
                       set : function (value) { element.value = value;} 


<input id="an-input" />
<input id="another-input" />

And to use:

var myVar = new variable(document.getElementById("an-input"));

// and another example:
var myVar2 = new variable(document.getElementById("another-input"));

A fancier way of doing the above without getter/setter:

var variable = function(element){

                return function () {
                    if(arguments.length > 0)                        
                        element.value = arguments[0];                                           

                    else return element.value;                                                  


To use:

var v1 = new variable(document.getElementById("an-input"));
v1(10); // sets value to 20.
console.log(v1()); // reads value.

Replace HTML Table with Divs

You can create simple float-based forms without having to lose your liquid layout. For example:

<style type="text/css">
    .row { clear: left; padding: 6px; }
    .row label { float: left; width: 10em; }
    .row .field { display: block; margin-left: 10em; }
    .row .field input, .row .field select {
        width: 100%;
        box-sizing: border-box;
        -moz-box-sizing: border-box; -webkit-box-sizing: border-box; -khtml-box-sizing: border-box;

<div class="row">
    <label for="f-firstname">First name</label>
    <span class="field"><input name="firstname" id="f-firstname" value="Bob" /></span>
<div class="row">
    <label for="f-state">State</label>
    <span class="field"><select name="state" id="f-state">
        <option value="NY">NY</option>

This does tend to break down, though, when you have complex form layouts where there's a grid of multiple fixed and flexible width columns. At that point you have to decide whether to stick with divs and abandon liquid layout in favour of just dropping everything into fixed pixel positions, or let tables do it.

For me personally, liquid layout is a more important usability feature than the exact elements used to lay out the form, so I usually go for tables.

Htaccess: add/remove trailing slash from URL

Options +FollowSymLinks
RewriteEngine On
RewriteBase /
## hide .html extension
# To externally redirect /dir/foo.html to /dir/foo
RewriteCond %{THE_REQUEST} ^[A-Z]{3,}\s([^.]+).html
RewriteRule ^ %1 [R=301,L]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,}\s([^.]+)/\s
RewriteRule ^ %1 [R=301,L]

## To internally redirect /dir/foo to /dir/foo.html
RewriteCond %{REQUEST_FILENAME}.html -f
RewriteRule ^([^\.]+)$ $1.html [L]

<Files ~"^.*\.([Hh][Tt][Aa])">
order allow,deny
deny from all
satisfy all

This removes html code or php if you supplement it. Allows you to add trailing slash and it come up as well as the url without the trailing slash all bypassing the 404 code. Plus a little added security.

How do I tar a directory of files and folders without including the directory itself?


find /my/dir/ -printf "%P\n" | tar -czf mydir.tgz --no-recursion -C /my/dir/ -T -

With some conditions (archive only files, dirs and symlinks):

find /my/dir/ -printf "%P\n" -type f -o -type l -o -type d | tar -czf mydir.tgz --no-recursion -C /my/dir/ -T -


The below unfortunately includes a parent directory ./ in the archive:

tar -czf mydir.tgz -C /my/dir .

You can move all the files out of that directory by using the --transform configuration option, but that doesn't get rid of the . directory itself. It becomes increasingly difficult to tame the command.

You could use $(find ...) to add a file list to the command (like in magnus' answer), but that potentially causes a "file list too long" error. The best way is to combine it with tar's -T option, like this:

find /my/dir/ -printf "%P\n" -type f -o -type l -o -type d | tar -czf mydir.tgz --no-recursion -C /my/dir/ -T -

Basically what it does is list all files (-type f), links (-type l) and subdirectories (-type d) under your directory, make all filenames relative using -printf "%P\n", and then pass that to the tar command (it takes filenames from STDIN using -T -). The -C option is needed so tar knows where the files with relative names are located. The --no-recursion flag is so that tar doesn't recurse into folders it is told to archive (causing duplicate files).

If you need to do something special with filenames (filtering, following symlinks etc), the find command is pretty powerful, and you can test it by just removing the tar part of the above command:

$ find /my/dir/ -printf "%P\n" -type f -o -type l -o -type d
> textfile.txt
> documentation.pdf
> subfolder2
> subfolder
> subfolder/.gitignore

For example if you want to filter PDF files, add ! -name '*.pdf'

$ find /my/dir/ -printf "%P\n" -type f ! -name '*.pdf' -o -type l -o -type d
> textfile.txt
> subfolder2
> subfolder
> subfolder/.gitignore

Non-GNU find

The command uses printf (available in GNU find) which tells find to print its results with relative paths. However, if you don't have GNU find, this works to make the paths relative (removes parents with sed):

find /my/dir/ -type f -o -type l -o -type d | sed s,^/my/dir/,, | tar -czf mydir.tgz --no-recursion -C /my/dir/ -T -

Remove array element based on object property

Using lodash library it is simple as this

_.remove(myArray , { field: 'money' });