Programs & Examples On #Line segment

Shortest distance between a point and a line segment

WPF version:

public class LineSegment
{
    private readonly Vector _offset;
    private readonly Vector _vector;

    public LineSegment(Point start, Point end)
    {
        _offset = (Vector)start;
        _vector = (Vector)(end - _offset);
    }

    public double DistanceTo(Point pt)
    {
        var v = (Vector)pt - _offset;

        // first, find a projection point on the segment in parametric form (0..1)
        var p = (v * _vector) / _vector.LengthSquared;

        // and limit it so it lays inside the segment
        p = Math.Min(Math.Max(p, 0), 1);

        // now, find the distance from that point to our point
        return (_vector * p - v).Length;
    }
}

Failed to connect to camera service

since this question was asked 4 years back..and i didn't realised that unless mentioned by the Questioner..when there were no Run time permissions support.

but hoping it useful for the users who still caught in this situation.. Have a look at Run Time Permissions ,for me it solved the problem when i added Run time permissions to grant camera access. Alternatively you can grant permissions to the app manually by going to your mobile settings=>Apps=>(select your app)=>Permissions section in the appeared window and enable/disable desired permissions. hope this will work.

Serializing with Jackson (JSON) - getting "No serializer found"?

If you can edit the class containing that object, I usually just add the annotation

import com.fasterxml.jackson.annotation.JsonIgnore;

@JsonIgnore 
NonSerializeableClass obj;

How can I send large messages with Kafka (over 15MB)?

One key thing to remember that message.max.bytes attribute must be in sync with the consumer's fetch.message.max.bytes property. the fetch size must be at least as large as the maximum message size otherwise there could be situation where producers can send messages larger than the consumer can consume/fetch. It might worth taking a look at it.
Which version of Kafka you are using? Also provide some more details trace that you are getting. is there some thing like ... payload size of xxxx larger than 1000000 coming up in the log?

org.apache.poi.POIXMLException: org.apache.poi.openxml4j.exceptions.InvalidFormatException:

You are trying to access an XLS file. However, you are using XSSFWorkbook and XSSFSheet class objects. These classes are mainly used for XLSX files.

For XLS file: HSSFWorkbook & HSSFSheet
For XLSX file: XSSFSheet & XSSFSheet

So in place of XSSFWorkbook use HSSFWorkbook and in place of XSSFSheet use HSSFSheet.

So your code should look like this after the changes are made:

HSSFWorkbook workbook = new HSSFWorkbook(file);

HSSFSheet sheet = workbook.getSheetAt(0);

Passing by reference in C

What you are doing is pass by value not pass by reference. Because you are sending the value of a variable 'p' to the function 'f' (in main as f(p);)

The same program in C with pass by reference will look like,(!!!this program gives 2 errors as pass by reference is not supported in C)

#include <stdio.h>

void f(int &j) {    //j is reference variable to i same as int &j = i
  j++;
}

int main() {
  int i = 20;
  f(i);
  printf("i = %d\n", i);

  return 0;
}

Output:-

3:12: error: expected ';', ',' or ')' before '&' token
             void f(int &j);
                        ^
9:3:  warning: implicit declaration of function 'f'
               f(a);
               ^

Unable to run Java code with Intellij IDEA

Sometimes, patience is key.

I had the same problem with a java project with big node_modules / .m2 directories.
The indexing was very long so I paused it and it prevented me from using Run Configurations.

So I waited for the indexing to finish and only then I was able to run my main class.

Distribution certificate / private key not installed

If you are being stuck on this problem. After switch the computer and not able to upload your build to App Store. Simply click manage certificate on the error page, the + plus on the bottom left corner and create a new distribution certificate. Then you'll be good to go.

Remove Rows From Data Frame where a Row matches a String

I had a column(A) in a data frame with 3 values in it (yes, no, unknown). I wanted to filter only those rows which had a value "yes" for which this is the code, hope this will help you guys as well --

df <- df [(!(df$A=="no") & !(df$A=="unknown")),]

Which sort algorithm works best on mostly sorted data?

If you are in need of specific implementation for sorting algorithms, data structures or anything that have a link to the above, could I recommend you the excellent "Data Structures and Algorithms" project on CodePlex?

It will have everything you need without reinventing the wheel.

Just my little grain of salt.

SQL Column definition : default value and not null redundant?

My SQL teacher said that if you specify both a DEFAULT value and NOT NULLor NULL, DEFAULT should always be expressed before NOT NULL or NULL.

Like this:

ALTER TABLE tbl ADD COLUMN col VARCHAR(20) DEFAULT "MyDefault" NOT NULL

ALTER TABLE tbl ADD COLUMN col VARCHAR(20) DEFAULT "MyDefault" NULL

Swift days between two NSDates

let calendar = NSCalendar.currentCalendar();
let component1 = calendar.component(.Day, fromDate: fromDate)
let component2 = calendar.component(.Day, fromDate: toDate)
let difference  = component1 - component2

Go to beginning of line without opening new line in VI

There is another way:

|

That is the "pipe" - the symbol found under the backspace in ANSI layout.

Vim quickref (:help quickref) describes it as:

N      |      to column N (default: 1)

What about wrapped lines?

If you have wrap lines enabled, 0 and | will no longer take you to the beginning of the screen line. In that case use:

g0

Again, vim quickref doc:

 g0   to first character in screen line (differs from "0"
      when lines wrap)

Understanding .get() method in Python

I see this is a fairly old question, but this looks like one of those times when something's been written without knowledge of a language feature. The collections library exists to fulfill these purposes.

from collections import Counter
letter_counter = Counter()
for letter in 'The quick brown fox jumps over the lazy dog':
    letter_counter[letter] += 1

>>> letter_counter
Counter({' ': 8, 'o': 4, 'e': 3, 'h': 2, 'r': 2, 'u': 2, 'T': 1, 'a': 1, 'c': 1, 'b': 1, 'd': 1, 'g': 1, 'f': 1, 'i': 1, 'k': 1, 'j': 1, 'm': 1, 'l': 1, 'n': 1, 'q': 1, 'p': 1, 's': 1, 't': 1, 'w': 1, 'v': 1, 'y': 1, 'x': 1, 'z': 1})

In this example the spaces are being counted, obviously, but whether or not you want those filtered is up to you.

As for the dict.get(a_key, default_value), there have been several answers to this particular question -- this method returns the value of the key, or the default_value you supply. The first argument is the key you're looking for, the second argument is the default for when that key is not present.

Can I run CUDA on Intel's integrated graphics processor?

At the present time, Intel graphics chips do not support CUDA. It is possible that, in the nearest future, these chips will support OpenCL (which is a standard that is very similar to CUDA), but this is not guaranteed and their current drivers do not support OpenCL either. (There is an Intel OpenCL SDK available, but, at the present time, it does not give you access to the GPU.)

Newest Intel processors (Sandy Bridge) have a GPU integrated into the CPU core. Your processor may be a previous-generation version, in which case "Intel(HD) graphics" is an independent chip.

Create a branch in Git from another branch

Do simultaneous work on the dev branch. What happens is that in your scenario the feature branch moves forward from the tip of the dev branch, but the dev branch does not change. It's easier to draw as a straight line, because it can be thought of as forward motion. You made it to point A on dev, and from there you simply continued on a parallel path. The two branches have not really diverged.

Now, if you make a commit on dev, before merging, you will again begin at the same commit, A, but now features will go to C and dev to B. This will show the split you are trying to visualize, as the branches have now diverged.

*-----*Dev-------*Feature

Versus

       /----*DevB
*-----*DevA
       \----*FeatureC

What's the meaning of "=>" (an arrow formed from equals & greater than) in JavaScript?

What It Is

This is an arrow function. Arrow functions are a short syntax, introduced by ECMAscript 6, that can be used similarly to the way you would use function expressions. In other words, you can often use them in place of expressions like function (foo) {...}. But they have some important differences. For example, they do not bind their own values of this (see below for discussion).

Arrow functions are part of the ECMAscript 6 specification. They are not yet supported in all browsers, but they are partially or fully supported in Node v. 4.0+ and in most modern browsers in use as of 2018. (I’ve included a partial list of supporting browsers below).

You can read more in the Mozilla documentation on arrow functions.

From the Mozilla documentation:

An arrow function expression (also known as fat arrow function) has a shorter syntax compared to function expressions and lexically binds the this value (does not bind its own this, arguments, super, or new.target). Arrow functions are always anonymous. These function expressions are best suited for non-method functions and they can not be used as constructors.

A Note on How this Works in Arrow Functions

One of the most handy features of an arrow function is buried in the text above:

An arrow function... lexically binds the this value (does not bind its own this...)

What this means in simpler terms is that the arrow function retains the this value from its context and does not have its own this. A traditional function may bind its own this value, depending on how it is defined and called. This can require lots of gymnastics like self = this;, etc., to access or manipulate this from one function inside another function. For more info on this topic, see the explanation and examples in the Mozilla documentation.

Example Code

Example (also from the docs):

var a = [
  "We're up all night 'til the sun",
  "We're up all night to get some",
  "We're up all night for good fun",
  "We're up all night to get lucky"
];

// These two assignments are equivalent:

// Old-school:
var a2 = a.map(function(s){ return s.length });

// ECMAscript 6 using arrow functions
var a3 = a.map( s => s.length );

// both a2 and a3 will be equal to [31, 30, 31, 31]

Notes on Compatibility

You can use arrow functions in Node, but browser support is spotty.

Browser support for this functionality has improved quite a bit, but it still is not widespread enough for most browser-based usages. As of December 12, 2017, it is supported in current versions of:

  • Chrome (v. 45+)
  • Firefox (v. 22+)
  • Edge (v. 12+)
  • Opera (v. 32+)
  • Android Browser (v. 47+)
  • Opera Mobile (v. 33+)
  • Chrome for Android (v. 47+)
  • Firefox for Android (v. 44+)
  • Safari (v. 10+)
  • iOS Safari (v. 10.2+)
  • Samsung Internet (v. 5+)
  • Baidu Browser (v. 7.12+)

Not supported in:

  • IE (through v. 11)
  • Opera Mini (through v. 8.0)
  • Blackberry Browser (through v. 10)
  • IE Mobile (through v. 11)
  • UC Browser for Android (through v. 11.4)
  • QQ (through v. 1.2)

You can find more (and more current) information at CanIUse.com (no affiliation).

Excel: Use a cell value as a parameter for a SQL query

I had the same problem as you, Noboby can understand me, But I solved it in this way.

SELECT NAME, TELEFONE, DATA
FROM   [sheet1$a1:q633]
WHERE  NAME IN (SELECT * FROM  [sheet2$a1:a2])

you need insert a parameter in other sheet, the SQL will consider that information like as database, then you can select the information and compare them into parameter you like.

How do I add the contents of an iterable to a set?

For the benefit of anyone who might believe e.g. that doing aset.add() in a loop would have performance competitive with doing aset.update(), here's an example of how you can test your beliefs quickly before going public:

>\python27\python -mtimeit -s"it=xrange(10000);a=set(xrange(100))" "a.update(it)"
1000 loops, best of 3: 294 usec per loop

>\python27\python -mtimeit -s"it=xrange(10000);a=set(xrange(100))" "for i in it:a.add(i)"
1000 loops, best of 3: 950 usec per loop

>\python27\python -mtimeit -s"it=xrange(10000);a=set(xrange(100))" "a |= set(it)"
1000 loops, best of 3: 458 usec per loop

>\python27\python -mtimeit -s"it=xrange(20000);a=set(xrange(100))" "a.update(it)"
1000 loops, best of 3: 598 usec per loop

>\python27\python -mtimeit -s"it=xrange(20000);a=set(xrange(100))" "for i in it:a.add(i)"
1000 loops, best of 3: 1.89 msec per loop

>\python27\python -mtimeit -s"it=xrange(20000);a=set(xrange(100))" "a |= set(it)"
1000 loops, best of 3: 891 usec per loop

Looks like the cost per item of the loop approach is over THREE times that of the update approach.

Using |= set() costs about 1.5x what update does but half of what adding each individual item in a loop does.

How to store file name in database, with other info while uploading image to server using PHP?

If you want to input more data into the form, you simply access the submitted data through $_POST.

If you have

<input type="text" name="firstname" />

you access it with

$firstname = $_POST["firstname"];

You could then update your query line to read

mysql_query("INSERT INTO dbProfiles (photo,firstname)
             VALUES('{$filename}','{$firstname}')");

Note: Always filter and sanitize your data.

return string with first match Regex

You shouldn't be using .findall() at all - .search() is what you want. It finds the leftmost match, which is what you want (or returns None if no match exists).

m = re.search(pattern, text)
result = m.group(0) if m else ""

Whether you want to put that in a function is up to you. It's unusual to want to return an empty string if no match is found, which is why nothing like that is built in. It's impossible to get confused about whether .search() on its own finds a match (it returns None if it didn't, or an SRE_Match object if it did).

clear cache of browser by command line

Here is how to clear all trash & caches (without other private data in browsers) by a command line. This is a command line batch script that takes care of all trash (as of April 2014):

erase "%TEMP%\*.*" /f /s /q
for /D %%i in ("%TEMP%\*") do RD /S /Q "%%i"

erase "%TMP%\*.*" /f /s /q
for /D %%i in ("%TMP%\*") do RD /S /Q "%%i"

erase "%ALLUSERSPROFILE%\TEMP\*.*" /f /s /q
for /D %%i in ("%ALLUSERSPROFILE%\TEMP\*") do RD /S /Q "%%i"

erase "%SystemRoot%\TEMP\*.*" /f /s /q
for /D %%i in ("%SystemRoot%\TEMP\*") do RD /S /Q "%%i"


@rem Clear IE cache -  (Deletes Temporary Internet Files Only)
RunDll32.exe InetCpl.cpl,ClearMyTracksByProcess 8
erase "%LOCALAPPDATA%\Microsoft\Windows\Tempor~1\*.*" /f /s /q
for /D %%i in ("%LOCALAPPDATA%\Microsoft\Windows\Tempor~1\*") do RD /S /Q "%%i"

@rem Clear Google Chrome cache
erase "%LOCALAPPDATA%\Google\Chrome\User Data\*.*" /f /s /q
for /D %%i in ("%LOCALAPPDATA%\Google\Chrome\User Data\*") do RD /S /Q "%%i"


@rem Clear Firefox cache
erase "%LOCALAPPDATA%\Mozilla\Firefox\Profiles\*.*" /f /s /q
for /D %%i in ("%LOCALAPPDATA%\Mozilla\Firefox\Profiles\*") do RD /S /Q "%%i"

pause

I am pretty sure it will run for some time when you first run it :) Enjoy!

How to get UTC time in Python?

import datetime
import pytz

# datetime object with timezone awareness:
datetime.datetime.now(tz=pytz.utc)

# seconds from epoch:
datetime.datetime.now(tz=pytz.utc).timestamp() 

# ms from epoch:
int(datetime.datetime.now(tz=pytz.utc).timestamp() * 1000) 

How do I minimize the command prompt from my bat file

There is a quite interesting way to execute script minimized by making him restart itself minimised. Here is the code to put in the beginning of your script:

if not DEFINED IS_MINIMIZED set IS_MINIMIZED=1 && start "" /min "%~dpnx0" %* && exit
... script logic here ...
exit

How it works

When the script is being executed IS_MINIMIZED is not defined (if not DEFINED IS_MINIMIZED) so:

  1. IS_MINIMIZED is set to 1: set IS_MINIMIZED=1.
  2. Script starts a copy of itself using start command && start "" /min "%~dpnx0" %* where:

    1. "" - empty title for the window.
    2. /min - switch to run minimized.
    3. "%~dpnx0" - full path to your script.
    4. %* - passing through all your script's parameters.
  3. Then initial script finishes its work: && exit.

For the started copy of the script variable IS_MINIMIZED is set by the original script so it just skips the execution of the first line and goes directly to the script logic.

Remarks

  • You have to reserve some variable name to use it as a flag.
  • The script should be ended with exit, otherwise the cmd window wouldn't be closed after the script execution.
  • If your script doesn't accept arguments you could use argument as a flag instead of variable:

    if "%1" == "" start "" /min "%~dpnx0" MY_FLAG && exit or shorter if "%1" == "" start "" /min "%~f0" MY_FLAG && exit

Are PostgreSQL column names case-sensitive?

The column names which are mixed case or uppercase have to be double quoted in PostgresQL. So best convention will be to follow all small case with underscore.

Setting up redirect in web.config file

In case that you need to add the http redirect in many sites, you could use it as a c# console program:

   class Program
{
    static int Main(string[] args)
    {
        if (args.Length < 3)
        {
            Console.WriteLine("Please enter an argument: for example insert-redirect ./web.config http://stackoverflow.com");
            return 1;
        }

        if (args.Length == 3)
        {
            if (args[0].ToLower() == "-insert-redirect")
            {
                var path = args[1];
                var value = args[2];

                if (InsertRedirect(path, value))
                    Console.WriteLine("Redirect added.");
                return 0;
            }
        }

        Console.WriteLine("Wrong parameters.");
        return 1;

    }

    static bool InsertRedirect(string path, string value)
    {
        try
        {
            XmlDocument doc = new XmlDocument();

            doc.Load(path);

            // This should find the appSettings node (should be only one):
            XmlNode nodeAppSettings = doc.SelectSingleNode("//system.webServer");

            var existNode = nodeAppSettings.SelectSingleNode("httpRedirect");
            if (existNode != null)
                return false;

            // Create new <add> node
            XmlNode nodeNewKey = doc.CreateElement("httpRedirect");

            XmlAttribute attributeEnable = doc.CreateAttribute("enabled");
            XmlAttribute attributeDestination = doc.CreateAttribute("destination");
            //XmlAttribute attributeResponseStatus = doc.CreateAttribute("httpResponseStatus");

            // Assign values to both - the key and the value attributes:

            attributeEnable.Value = "true";
            attributeDestination.Value = value;
            //attributeResponseStatus.Value = "Permanent";

            // Add both attributes to the newly created node:
            nodeNewKey.Attributes.Append(attributeEnable);
            nodeNewKey.Attributes.Append(attributeDestination);
            //nodeNewKey.Attributes.Append(attributeResponseStatus);

            // Add the node under the 
            nodeAppSettings.AppendChild(nodeNewKey);
            doc.Save(path);

            return true;
        }
        catch (Exception e)
        {
            Console.WriteLine($"Exception adding redirect: {e.Message}");
            return false;
        }
    }
}

How can I detect the encoding/codepage of a text file

Since it basically comes down to heuristics, it may help to use the encoding of previously received files from the same source as a first hint.

Most people (or applications) do stuff in pretty much the same order every time, often on the same machine, so its quite likely that when Bob creates a .csv file and sends it to Mary it'll always be using Windows-1252 or whatever his machine defaults to.

Where possible a bit of customer training never hurts either :-)

Text-align class for inside a table

Bootstrap 4 is coming! The utility classes made familiar in Bootstrap 3.x are now break-point enabled. The default breakpoints are: xs, sm, md, lg and xl, so these text alignment classes look something like .text-[breakpoint]-[alignnment].

<div class="text-sm-left"></div> //or
<div class="text-md-center"></div> //or
<div class="text-xl-right"></div>

Important: As of writing this, Bootstrap 4 is only in Alpha 2. These classes and how they're used are subject to change without notice.

How to send custom headers with requests in Swagger UI?

In ASP.NET Core 2 Web API, using Swashbuckle.AspNetCore package 2.1.0, implement a IDocumentFilter:

SwaggerSecurityRequirementsDocumentFilter.cs

using System.Collections.Generic;
using Swashbuckle.AspNetCore.Swagger;
using Swashbuckle.AspNetCore.SwaggerGen;

namespace api.infrastructure.filters
{
    public class SwaggerSecurityRequirementsDocumentFilter : IDocumentFilter
    {
        public void Apply(SwaggerDocument document, DocumentFilterContext context)
        {
            document.Security = new List<IDictionary<string, IEnumerable<string>>>()
            {
                new Dictionary<string, IEnumerable<string>>()
                {
                    { "Bearer", new string[]{ } },
                    { "Basic", new string[]{ } },
                }
            };
        }
    }
}

In Startup.cs, configure a security definition and register the custom filter:

public void ConfigureServices(IServiceCollection services)
{
    services.AddSwaggerGen(c =>
    {
        // c.SwaggerDoc(.....

        c.AddSecurityDefinition("Bearer", new ApiKeyScheme()
        {
            Description = "Authorization header using the Bearer scheme",
            Name = "Authorization",
            In = "header"
        });

        c.DocumentFilter<SwaggerSecurityRequirementsDocumentFilter>();
    });
}

In Swagger UI, click on Authorize button and set value for token.

Window to set value

Result:

curl -X GET "http://localhost:5000/api/tenants" -H "accept: text/plain" -H "Authorization: Bearer ABCD123456"

COUNT DISTINCT with CONDITIONS

This may also work:

SELECT 
    COUNT(DISTINCT T.tag) as DistinctTag,
    COUNT(DISTINCT T2.tag) as DistinctPositiveTag
FROM Table T
    LEFT JOIN Table T2 ON T.tag = T2.tag AND T.entryID = T2.entryID AND T2.entryID > 0

You need the entryID condition in the left join rather than in a where clause in order to make sure that any items that only have a entryID of 0 get properly counted in the first DISTINCT.

JPA & Criteria API - Select only specific columns

One of the JPA ways for getting only particular columns is to ask for a Tuple object.

In your case you would need to write something like this:

CriteriaQuery<Tuple> cq = builder.createTupleQuery();
// write the Root, Path elements as usual
Root<EntityClazz> root = cq.from(EntityClazz.class);
cq.multiselect(root.get(EntityClazz_.ID), root.get(EntityClazz_.VERSION));  //using metamodel
List<Tuple> tupleResult = em.createQuery(cq).getResultList();
for (Tuple t : tupleResult) {
    Long id = (Long) t.get(0);
    Long version = (Long) t.get(1);
}

Another approach is possible if you have a class representing the result, like T in your case. T doesn't need to be an Entity class. If T has a constructor like:

public T(Long id, Long version)

then you can use T directly in your CriteriaQuery constructor:

CriteriaQuery<T> cq = builder.createQuery(T.class);
// write the Root, Path elements as usual
Root<EntityClazz> root = cq.from(EntityClazz.class);
cq.multiselect(root.get(EntityClazz_.ID), root.get(EntityClazz_.VERSION));  //using metamodel
List<T> result = em.createQuery(cq).getResultList();

See this link for further reference.

ORA-28040: No matching authentication protocol exception

While for most cases replacing ojdbc driver jar will be the solution, my case was different.

If you are certain you are using correct ojdbc driver. Double check if you are actually connecting to the database you are thinking you are. In my case jdbc configuration (in Tomcat/conf) was pointing to different database that had different Oracle version.

Calling a JSON API with Node.js

Unirest library simplifies this a lot. If you want to use it, you have to install unirest npm package. Then your code could look like this:

unirest.get("http://graph.facebook.com/517267866/?fields=picture")
  .send()
  .end(response=> {
    if (response.ok) {
      console.log("Got a response: ", response.body.picture)
    } else {
      console.log("Got an error: ", response.error)
    }
  })

How can I get the source directory of a Bash script from within the script itself?

How to obtain the full file path, full directory, and base filename of any script being run itself

For many cases, all you need to acquire is the full path to the script you just called. This can be easily accomplished using realpath. Note that realpath is part of GNU coreutils. If you don't have it already installed (it comes default on Ubuntu), you can install it with sudo apt update && sudo apt install coreutils.

get_script_path.sh:

#!/bin/bash

FULL_PATH_TO_SCRIPT="$(realpath "$0")"

# You can then also get the full path to the directory, and the base
# filename, like this:
SCRIPT_DIRECTORY="$(dirname "$FULL_PATH_TO_SCRIPT")"
SCRIPT_FILENAME="$(basename "$FULL_PATH_TO_SCRIPT")"

# Now print it all out
echo "FULL_PATH_TO_SCRIPT = \"$FULL_PATH_TO_SCRIPT\""
echo "SCRIPT_DIRECTORY    = \"$SCRIPT_DIRECTORY\""
echo "SCRIPT_FILENAME     = \"$SCRIPT_FILENAME\""

Example output:

~/GS/dev/eRCaGuy_hello_world/bash$ ./get_script_path.sh 
FULL_PATH_TO_SCRIPT = "/home/gabriel/GS/dev/eRCaGuy_hello_world/bash/get_script_path.sh"
SCRIPT_DIRECTORY    = "/home/gabriel/GS/dev/eRCaGuy_hello_world/bash"
SCRIPT_FILENAME     = "get_script_path.sh"

Note that realpath also successfully walks down symbolic links to determine and point to their targets rather than pointing to the symbolic link.

The code above is now part of my eRCaGuy_hello_world repo in this file here: bash/get_script_path.sh.

References:

  1. How to retrieve absolute path given relative

How to create a directory using Ansible

You can create a directory. using

# create a directory if it doesn't exist
- file: path=/src/www state=directory mode=0755

You can also consult http://docs.ansible.com/ansible/file_module.html for further details regaridng directory and file system.

How to use curl to get a GET request exactly same as using Chrome?

If you need to set the user header string in the curl request, you can use the -H option to set user agent like:

curl -H "user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36" http://stackoverflow.com/questions/28760694/how-to-use-curl-to-get-a-get-request-exactly-same-as-using-chrome

Updated user-agent form newest Chrome at 02-22-2021


Using a proxy tool like Charles Proxy really helps make short work of something like what you are asking. Here is what I do, using this SO page as an example (as of July 2015 using Charles version 3.10):

  1. Get Charles Proxy running
  2. Make web request using browser
  3. Find desired request in Charles Proxy
  4. Right click on request in Charles Proxy
  5. Select 'Copy cURL Request'

Copy cURL Request example in Charles 3.10.2

You now have a cURL request you can run in a terminal that will mirror the request your browser made. Here is what my request to this page looked like (with the cookie header removed):

curl -H "Host: stackoverflow.com" -H "Cache-Control: max-age=0" -H "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8" -H "User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.89 Safari/537.36" -H "HTTPS: 1" -H "DNT: 1" -H "Referer: https://www.google.com/" -H "Accept-Language: en-US,en;q=0.8,en-GB;q=0.6,es;q=0.4" -H "If-Modified-Since: Thu, 23 Jul 2015 20:31:28 GMT" --compressed http://stackoverflow.com/questions/28760694/how-to-use-curl-to-get-a-get-request-exactly-same-as-using-chrome

Filter element based on .data() key/value

your filter would work, but you need to return true on matching objects in the function passed to the filter for it to grab them.

var $previous = $('.navlink').filter(function() { 
  return $(this).data("selected") == true 
});

Pandas - Plotting a stacked Bar Chart

If you want to change the size of plot the use arg figsize

df.groupby(['NFF', 'ABUSE']).size().unstack()
      .plot(kind='bar', stacked=True, figsize=(15, 5))

What is "export default" in JavaScript?

As explained on this MDN page

There are two different types of export, named and default. You can have multiple named exports per module but only one default export[...]Named exports are useful to export several values. During the import, it is mandatory to use the same name of the corresponding object.But a default export can be imported with any name

For example:

let myVar; export default myVar = 123; // in file my-module.js

import myExportedVar from './my-module' //  we have the freedom to use 'import myExportedVar' instead of 'import myVar' because myVar was defined as default export

console.log(myExportedVar);        // will log 123

Check if a user has scrolled to the bottom

I'm not exactly sure why this has not been posted yet, but as per the documentation from MDN, the simplest way is by using native javascript properties:

element.scrollHeight - element.scrollTop === element.clientHeight

Returns true when you're at the bottom of any scrollable element. So simply using javascript:

element.addEventListener('scroll', function(event)
{
    var element = event.target;
    if (element.scrollHeight - element.scrollTop === element.clientHeight)
    {
        console.log('scrolled');
    }
});

scrollHeight have wide support in browsers, from ie 8 to be more precise, while clientHeight and scrollTop are both supported by everyone. Even ie 6. This should be cross browser safe.

Validate phone number with JavaScript

This will work:

/^(()?\d{3}())?(-|\s)?\d{3}(-|\s)?\d{4}$/

The ? character signifies that the preceding group should be matched zero or one times. The group (-|\s) will match either a - or a | character. Adding ? after the second occurrence of this group in your regex allows you to match a sequence of 10 consecutive digits.

How do you split a list into evenly sized chunks?

I don't think I saw this option, so just to add another one :)) :

def chunks(iterable, chunk_size):
  i = 0;
  while i < len(iterable):
    yield iterable[i:i+chunk_size]
    i += chunk_size

Localhost : 404 not found

If your server is still listening on port 80, check the permission on the DocumentRoot folder and if DirectoryIndex file existed.

How to create a new object instance from a Type

public AbstractType New
{
    get
    {
        return (AbstractType) Activator.CreateInstance(GetType());
    }
}

Handle file download from ajax post

see: http://www.henryalgus.com/reading-binary-files-using-jquery-ajax/ it'll return a blob as a response, which can then be put into filesaver

Converting java.util.Properties to HashMap<String,String>

The problem is that Properties implements Map<Object, Object>, whereas the HashMap constructor expects a Map<? extends String, ? extends String>.

This answer explains this (quite counter-intuitive) decision. In short: before Java 5, Properties implemented Map (as there were no generics back then). This meant that you could put any Object in a Properties object. This is still in the documenation:

Because Properties inherits from Hashtable, the put and putAll methods can be applied to a Properties object. Their use is strongly discouraged as they allow the caller to insert entries whose keys or values are not Strings. The setProperty method should be used instead.

To maintain compatibility with this, the designers had no other choice but to make it inherit Map<Object, Object> in Java 5. It's an unfortunate result of the strive for full backwards compatibility which makes new code unnecessarily convoluted.

If you only ever use string properties in your Properties object, you should be able to get away with an unchecked cast in your constructor:

Map<String, String> map = new HashMap<String, String>( (Map<String, String>) properties);

or without any copies:

Map<String, String> map = (Map<String, String>) properties;

Switching to landscape mode in Android Emulator

For those of you with a Chromebook Pixel/Ubuntu/Crouton with no numpad, installing the onboard keyboard worked for me.

image of onboard software keyboard on ubuntu

Just press 123 to access the numpad layout, and then press 7

If you're on Unity already, onboard may already be installed, so just type onboard from your command line to see if it's there.

If not, just type:

sudo apt-get update

sudo apt-get install onboard

PS: The Chromebook Pixel's upper keys were supposed to represent the traditional F1 through F11 function keys on Ubuntu/Crouton, so you may want to try those special hardware keys first (on their own or in combination with Ctrl). It's just that for me, I'm running an old copy of Crouton, and the only function key that seems to be recognized is F6

jQuery: go to URL with target="_blank"

The .ready function is used to insert the attribute once the page has finished loading.

$(document).ready(function() {
     $("class name or id a.your class name").attr({"target" : "_blank"})
})

What is InputStream & Output Stream? Why and when do we use them?

InputStream is used for reading, OutputStream for writing. They are connected as decorators to one another such that you can read/write all different types of data from all different types of sources.

For example, you can write primitive data to a file:

File file = new File("C:/text.bin");
file.createNewFile();
DataOutputStream stream = new DataOutputStream(new FileOutputStream(file));
stream.writeBoolean(true);
stream.writeInt(1234);
stream.close();

To read the written contents:

File file = new File("C:/text.bin");
DataInputStream stream = new DataInputStream(new FileInputStream(file));
boolean isTrue = stream.readBoolean();
int value = stream.readInt();
stream.close();
System.out.printlin(isTrue + " " + value);

You can use other types of streams to enhance the reading/writing. For example, you can introduce a buffer for efficiency:

DataInputStream stream = new DataInputStream(
    new BufferedInputStream(new FileInputStream(file)));

You can write other data such as objects:

MyClass myObject = new MyClass(); // MyClass have to implement Serializable
ObjectOutputStream stream = new ObjectOutputStream(
    new FileOutputStream("C:/text.obj"));
stream.writeObject(myObject);
stream.close();

You can read from other different input sources:

byte[] test = new byte[] {0, 0, 1, 0, 0, 0, 1, 1, 8, 9};
DataInputStream stream = new DataInputStream(new ByteArrayInputStream(test));
int value0 = stream.readInt();
int value1 = stream.readInt();
byte value2 = stream.readByte();
byte value3 = stream.readByte();
stream.close();
System.out.println(value0 + " " + value1 + " " + value2 + " " + value3);

For most input streams there is an output stream, also. You can define your own streams to reading/writing special things and there are complex streams for reading complex things (for example there are Streams for reading/writing ZIP format).

Why are the Level.FINE logging messages not showing?

Tried other variants, this can be proper

    Logger logger = Logger.getLogger(MyClass.class.getName());        
    Level level = Level.ALL;
    for(Handler h : java.util.logging.Logger.getLogger("").getHandlers())    
        h.setLevel(level);
    logger.setLevel(level);
// this must be shown
    logger.fine("fine");
    logger.info("info");

Undefined class constant 'MYSQL_ATTR_INIT_COMMAND' with pdo

Using the int value 1002 seems to work for PHP 5.3.0:

public static function createDB() {
    $dbHost="localhost";
    $dbName="project";
    $dbUser="admin";
    $dbPassword="whatever";
    $dbOptions=array(1002 => 'SET NAMES utf8',);
    return new DB($dbHost, $dbName, $dbUser, $dbPassword,$dbOptions);
}

function createConnexion() {
    return new PDO(
        "mysql:host=$this->dbHost;dbname=$this->dbName",
        $this->dbUser,
        $this->dbPassword,
        $this->dbOptions); 
}

Storing and Retrieving ArrayList values from hashmap

for (Map.Entry<String, ArrayList<Integer>> entry : map.entrySet()) {
 System.out.println( entry.getKey());     
 System.out.println( entry.getValue());//Returns the list of values
}

ERROR: Google Maps API error: MissingKeyMapError

The script element that loads the API is missing the required authentication parameter. If you are using the standard Maps JavaScript API, you must use a key parameter with a valid API key. If you are a Premium Plan customer, you must use either a client parameter with your client ID or a key parameter with a valid API key.

See the guide to API keys and client IDs.

Prompt for user input in PowerShell

As an alternative, you could add it as a script parameter for input as part of script execution

 param(
      [Parameter(Mandatory = $True,valueFromPipeline=$true)][String] $value1,
      [Parameter(Mandatory = $True,valueFromPipeline=$true)][String] $value2
      )

Set up Python simpleHTTPserver on Windows

From Stack Overflow question What is the Python 3 equivalent of "python -m SimpleHTTPServer":

The following works for me:

python -m http.server [<portNo>]

Because I am using Python 3 the module SimpleHTTPServer has been replaced by http.server, at least in Windows.

How can I match a string with a regex in Bash?

A Function To Do This

extract () {
  if [ -f $1 ] ; then
      case $1 in
          *.tar.bz2)   tar xvjf $1    ;;
          *.tar.gz)    tar xvzf $1    ;;
          *.bz2)       bunzip2 $1     ;;
          *.rar)       rar x $1       ;;
          *.gz)        gunzip $1      ;;
          *.tar)       tar xvf $1     ;;
          *.tbz2)      tar xvjf $1    ;;
          *.tgz)       tar xvzf $1    ;;
          *.zip)       unzip $1       ;;
          *.Z)         uncompress $1  ;;
          *.7z)        7z x $1        ;;
          *)           echo "don't know '$1'..." ;;
      esac
  else
      echo "'$1' is not a valid file!"
  fi
}

Other Note

In response to Aquarius Power in the comment above, We need to store the regex on a var

The variable BASH_REMATCH is set after you match the expression, and ${BASH_REMATCH[n]} will match the nth group wrapped in parentheses ie in the following ${BASH_REMATCH[1]} = "compressed" and ${BASH_REMATCH[2]} = ".gz"

if [[ "compressed.gz" =~ ^(.*)(\.[a-z]{1,5})$ ]]; 
then 
  echo ${BASH_REMATCH[2]} ; 
else 
  echo "Not proper format"; 
fi

(The regex above isn't meant to be a valid one for file naming and extensions, but it works for the example)

Adding an image to a project in Visual Studio

If you're having an issue where the Resources added are images and are not getting copied to your build folder on compiling. You need to change the "Build Action" to None from Resource ( which is the default) and change the Copy to "If Newer" or "Always" as shown below :

enter image description here

How do I get ASP.NET Web API to return JSON instead of XML using Chrome?

Using Felipe Leusin's answer for years, after a recent update of core libraries and of Json.Net, I ran into a System.MissingMethodException:SupportedMediaTypes. The solution in my case, hopefully helpful to others experiencing the same unexpected exception, is to install System.Net.Http. NuGet apparently removes it in some circumstances. After a manual installation, the issue was resolved.

How to find if an array contains a specific string in JavaScript/jQuery?

Here you go:

$.inArray('specialword', arr)

This function returns a positive integer (the array index of the given value), or -1 if the given value was not found in the array.

Live demo: http://jsfiddle.net/simevidas/5Gdfc/

You probably want to use this like so:

if ( $.inArray('specialword', arr) > -1 ) {
    // the value is in the array
}

AcquireConnection method call to the connection manager <Excel Connection Manager> failed with error code 0xC0202009

I had similar issue just that excel was the destination in my case instead of source as in the case of the original question/issue. I have spent hours to resolve this issue but looks like finally Soniya Parmar saved the day for me. I have set job and let it run for few iterations already and all is good now. As per her suggestion I set up the delay validation of the Excel connection manager to 'True. Thanks Soniya

check / uncheck checkbox using jquery?

You can use prop() for this, as Before jQuery 1.6, the .attr() method sometimes took property values into account when retrieving some attributes, which could cause inconsistent behavior. As of jQuery 1.6, the .prop() method provides a way to explicitly retrieve property values, while .attr() retrieves attributes.

var prop=false;
if(value == 1) {
   prop=true; 
}
$('#checkbox').prop('checked',prop);

or simply,

$('#checkbox').prop('checked',(value == 1));

Snippet

_x000D_
_x000D_
$(document).ready(function() {_x000D_
  var chkbox = $('.customcheckbox');_x000D_
  $(".customvalue").keyup(function() {_x000D_
    chkbox.prop('checked', this.value==1);_x000D_
  });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<h4>This is a domo to show check box is checked_x000D_
if you enter value 1 else check box will be unchecked </h4>_x000D_
Enter a value:_x000D_
<input type="text" value="" class="customvalue">_x000D_
<br>checkbox output :_x000D_
<input type="checkbox" class="customcheckbox">
_x000D_
_x000D_
_x000D_

Pretty printing JSON from Jackson 2.2's ObjectMapper

If others who view this question only have a JSON string (not in an object), then you can put it into a HashMap and still get the ObjectMapper to work. The result variable is your JSON string.

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.util.HashMap;
import java.util.Map;

// Pretty-print the JSON result
try {
    ObjectMapper objectMapper = new ObjectMapper();
    Map<String, Object> response = objectMapper.readValue(result, HashMap.class);
    System.out.println(objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(response));
} catch (JsonParseException e) {
    e.printStackTrace();
} catch (JsonMappingException e) {
    e.printStackTrace();
} catch (IOException e) {
    e.printStackTrace();
} 

What is the path that Django uses for locating and loading templates?

basically BASE_DIR is your django project directory, same dir where manage.py is.

    TEMPLATES = [
        {
            'BACKEND': 'django.template.backends.django.DjangoTemplates',
            'DIRS': [os.path.join(BASE_DIR, 'templates')],
            'APP_DIRS': True,
            'OPTIONS': {
                'context_processors': [
                    'django.template.context_processors.debug',
                    'django.template.context_processors.request',
                    'django.contrib.auth.context_processors.auth',
                    'django.contrib.messages.context_processors.messages',
                ],
            },
        },
    ]

Mockito : doAnswer Vs thenReturn

doAnswer and thenReturn do the same thing if:

  1. You are using Mock, not Spy
  2. The method you're stubbing is returning a value, not a void method.

Let's mock this BookService

public interface BookService {
    String getAuthor();
    void queryBookTitle(BookServiceCallback callback);
}

You can stub getAuthor() using doAnswer and thenReturn.

BookService service = mock(BookService.class);
when(service.getAuthor()).thenReturn("Joshua");
// or..
doAnswer(new Answer() {
    @Override
    public Object answer(InvocationOnMock invocation) throws Throwable {
        return "Joshua";
    }
}).when(service).getAuthor();

Note that when using doAnswer, you can't pass a method on when.

// Will throw UnfinishedStubbingException
doAnswer(invocation -> "Joshua").when(service.getAuthor());

So, when would you use doAnswer instead of thenReturn? I can think of two use cases:

  1. When you want to "stub" void method.

Using doAnswer you can do some additionals actions upon method invocation. For example, trigger a callback on queryBookTitle.

BookServiceCallback callback = new BookServiceCallback() {
    @Override
    public void onSuccess(String bookTitle) {
        assertEquals("Effective Java", bookTitle);
    }
};
doAnswer(new Answer() {
    @Override
    public Object answer(InvocationOnMock invocation) throws Throwable {
        BookServiceCallback callback = (BookServiceCallback) invocation.getArguments()[0];
        callback.onSuccess("Effective Java");
        // return null because queryBookTitle is void
        return null;
    }
}).when(service).queryBookTitle(callback);
service.queryBookTitle(callback);
  1. When you are using Spy instead of Mock

When using when-thenReturn on Spy Mockito will call real method and then stub your answer. This can cause a problem if you don't want to call real method, like in this sample:

List list = new LinkedList();
List spy = spy(list);
// Will throw java.lang.IndexOutOfBoundsException: Index: 0, Size: 0
when(spy.get(0)).thenReturn("java");
assertEquals("java", spy.get(0));

Using doAnswer we can stub it safely.

List list = new LinkedList();
List spy = spy(list);
doAnswer(invocation -> "java").when(spy).get(0);
assertEquals("java", spy.get(0));

Actually, if you don't want to do additional actions upon method invocation, you can just use doReturn.

List list = new LinkedList();
List spy = spy(list);
doReturn("java").when(spy).get(0);
assertEquals("java", spy.get(0));

Check if a time is between two times (time DataType)

I suspect you want to check that it's after 11pm or before 7am:

select *
from MyTable
where CAST(Created as time) >= '23:00:00' 
   or CAST(Created as time) < '07:00:00'

Oracle pl-sql escape character (for a " ' ")

Your question implies that you're building the INSERT statement up by concatenating strings together. I suggest that this is a poor choice as it leaves you open to SQL injection attacks if the strings are derived from user input. A better choice is to use parameter markers and to bind the values to the markers. If you search for Oracle parameter markers you'll probably find some information for your specific implementation technology (e.g. C# and ADO, Java and JDBC, Ruby and RubyDBI, etc).

Share and enjoy.

A better way to check if a path exists or not in PowerShell

Add the following aliases. I think these should be made available in PowerShell by default:

function not-exist { -not (Test-Path $args) }
Set-Alias !exist not-exist -Option "Constant, AllScope"
Set-Alias exist Test-Path -Option "Constant, AllScope"

With that, the conditional statements will change to:

if (exist $path) { ... }

and

if (not-exist $path) { ... }
if (!exist $path) { ... }

How to filter Android logcat by application?

On Linux/Un*X/Cygwin you can get list of all tags in project (with appended :V after each) with this command (split because readability):

$ git grep 'String\s\+TAG\s*=\s*' |  \
  perl -ne 's/.*String\s+TAG\s*=\s*"?([^".]+).*;.*/$1:V/g && print ' | \
  sort | xargs
AccelerometerListener:V ADNList:V Ashared:V AudioDialog:V BitmapUtils:V # ...

It covers tags defined both ways of defining tags:

private static final String TAG = "AudioDialog";
private static final String TAG = SipProfileDb.class.getSimpleName();

And then just use it for adb logcat.

Sort an Array by keys based on another Array?

I used the Darkwaltz4's solution but used array_fill_keys instead of array_flip, to fill with NULL if a key is not set in $array.

$properOrderedArray = array_replace(array_fill_keys($keys, null), $array);

What causes: "Notice: Uninitialized string offset" to appear?

The error may occur when the number of times you iterate the array is greater than the actual size of the array. for example:

 $one="909";
 for($i=0;$i<10;$i++)
    echo ' '.$one[$i];

will show the error. first case u can take the mod of i.. for example

function mod($i,$length){
  $m = $i % $size;
  if ($m > $size)
  mod($m,$size)
  return $m;
}

for($i=0;$i<10;$i++)
{
  $k=mod($i,3);
  echo ' '.$one[$k];
}

or might be it not an array (maybe it was a value and you tried to access it like an array) for example:

$k = 2;
$k[0];

Is it possible to delete an object's property in PHP?

This also works specially if you are looping over an object.

unset($object[$key])

Update

Newer versions of PHP throw fatal error Fatal error: Cannot use object of type Object as array as mentioned by @CXJ . In that case you can use brackets instead

unset($object->{$key})

Saving response from Requests to file

You can use the response.text to write to a file:

import requests

files = {'f': ('1.pdf', open('1.pdf', 'rb'))}
response = requests.post("https://pdftables.com/api?&format=xlsx-single",files=files)
response.raise_for_status() # ensure we notice bad responses
file = open("resp_text.txt", "w")
file.write(response.text)
file.close()
file = open("resp_content.txt", "w")
file.write(response.text)
file.close()

Best timing method in C?

High resolution is relative... I was looking at the examples and they mostly cater for milliseconds. However for me it is important to measure microseconds. I have not seen a platform independant solution for microseconds and thought something like the code below will be usefull. I was timing on windows only for the time being and will most likely add a gettimeofday() implementation when doing the same on AIX/Linux.

    #ifdef WIN32
      #ifndef PERFTIME
        #include <windows.h>
        #include <winbase.h>
        #define PERFTIME_INIT unsigned __int64 freq;  QueryPerformanceFrequency((LARGE_INTEGER*)&freq); double timerFrequency = (1.0/freq);  unsigned __int64 startTime;  unsigned __int64 endTime;  double timeDifferenceInMilliseconds;
        #define PERFTIME_START QueryPerformanceCounter((LARGE_INTEGER *)&startTime);
        #define PERFTIME_END QueryPerformanceCounter((LARGE_INTEGER *)&endTime); timeDifferenceInMilliseconds = ((endTime-startTime) * timerFrequency);  printf("Timing %fms\n",timeDifferenceInMilliseconds);
    #define PERFTIME(funct) {unsigned __int64 freq;  QueryPerformanceFrequency((LARGE_INTEGER*)&freq);  double timerFrequency = (1.0/freq);  unsigned __int64 startTime;  QueryPerformanceCounter((LARGE_INTEGER *)&startTime);  unsigned __int64 endTime;  funct; QueryPerformanceCounter((LARGE_INTEGER *)&endTime);  double timeDifferenceInMilliseconds = ((endTime-startTime) * timerFrequency);  printf("Timing %fms\n",timeDifferenceInMilliseconds);}
      #endif
    #else
      //AIX/Linux gettimeofday() implementation here
    #endif

Usage:

PERFTIME(ProcessIntenseFunction());

or

PERFTIME_INIT
PERFTIME_START
ProcessIntenseFunction()
PERFTIME_END

Maintain image aspect ratio when changing height

Most of images with intrinsic dimensions, that is a natural size, like a jpeg image. If the specified size defines one of both the width and the height, the missing value is determined using the intrinsic ratio... - see MDN.

But that doesn't work as expected if the images that are being set as direct flex items with the current Flexible Box Layout Module Level 1, as far as I know.

See these discussions and bug reports might be related:

  • Flexbugs #14 - Chrome/Flexbox Intrinsic Sizing not implemented correctly.
  • Firefox Bug 972595 - Flex containers should use "flex-basis" instead of "width" for computing intrinsic widths of flex items
  • Chromium Issue 249112 - In Flexbox, allow intrinsic aspect ratios to inform the main-size calculation.

As a workaround, you could wrap each <img> with a <div> or a <span>, or so.

jsFiddle

_x000D_
_x000D_
.slider {_x000D_
  display: flex;_x000D_
}_x000D_
_x000D_
.slider>div {_x000D_
  min-width: 0; /* why? see below. */_x000D_
}_x000D_
_x000D_
.slider>div>img {_x000D_
  max-width: 100%;_x000D_
  height: auto;_x000D_
}
_x000D_
<div class="slider">_x000D_
  <div><img src="https://picsum.photos/400/300?image=0" /></div>_x000D_
  <div><img src="https://picsum.photos/400/300?image=1" /></div>_x000D_
  <div><img src="https://picsum.photos/400/300?image=2" /></div>_x000D_
  <div><img src="https://picsum.photos/400/300?image=3" /></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

4.5 Implied Minimum Size of Flex Items

To provide a more reasonable default minimum size for flex items, this specification introduces a new auto value as the initial value of the min-width and min-height properties defined in CSS 2.1.


Alternatively, you can use CSS table layout instead, which you'll get similar results as flexbox, it will work on more browsers, even for IE8.

jsFiddle

_x000D_
_x000D_
.slider {_x000D_
  display: table;_x000D_
  width: 100%;_x000D_
  table-layout: fixed;_x000D_
  border-collapse: collapse;_x000D_
}_x000D_
_x000D_
.slider>div {_x000D_
  display: table-cell;_x000D_
  vertical-align: top;_x000D_
}_x000D_
_x000D_
.slider>div>img {_x000D_
  max-width: 100%;_x000D_
  height: auto;_x000D_
}
_x000D_
<div class="slider">_x000D_
  <div><img src="https://picsum.photos/400/300?image=0" /></div>_x000D_
  <div><img src="https://picsum.photos/400/300?image=1" /></div>_x000D_
  <div><img src="https://picsum.photos/400/300?image=2" /></div>_x000D_
  <div><img src="https://picsum.photos/400/300?image=3" /></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to copy a dictionary and only edit the copy

The best and the easiest ways to create a copy of a dict in both Python 2.7 and 3 are...

To create a copy of simple(single-level) dictionary:

1. Using dict() method, instead of generating a reference that points to the existing dict.

my_dict1 = dict()
my_dict1["message"] = "Hello Python"
print(my_dict1)  # {'message':'Hello Python'}

my_dict2 = dict(my_dict1)
print(my_dict2)  # {'message':'Hello Python'}

# Made changes in my_dict1 
my_dict1["name"] = "Emrit"
print(my_dict1)  # {'message':'Hello Python', 'name' : 'Emrit'}
print(my_dict2)  # {'message':'Hello Python'}

2. Using the built-in update() method of python dictionary.

my_dict2 = dict()
my_dict2.update(my_dict1)
print(my_dict2)  # {'message':'Hello Python'}

# Made changes in my_dict1 
my_dict1["name"] = "Emrit"
print(my_dict1)  # {'message':'Hello Python', 'name' : 'Emrit'}
print(my_dict2)  # {'message':'Hello Python'}

To create a copy of nested or complex dictionary:

Use the built-in copy module, which provides a generic shallow and deep copy operations. This module is present in both Python 2.7 and 3.*

import copy

my_dict2 = copy.deepcopy(my_dict1)

INSTALL_FAILED_USER_RESTRICTED : android studio using redmi 4 device

For MIUI 9.6 works:
1. Become a developer: Settings >> About phone >> MIUI version tap 7 times.

2. Again Settings >> Additional settings >> Developer options (turn on) >> USB debugging (turn on) >> Install via USB (turn on).

3. You will be asked for permission through your MI account. Confirm permission.

4. Note: During the installation of the application, your device will give you 7 seconds to confirm the installation. Don't miss it!

Javascript isnull

Why not try .test() ? ... Try its and best boolean (true or false):

$.urlParam = function(name){
    var results = new RegExp('[\\?&]' + name + '=([^&#]*)');
    return results.test(window.location.href);
}

Tutorial: http://www.w3schools.com/jsref/jsref_regexp_test.asp

T-SQL How to create tables dynamically in stored procedures?

You can write the below code:-

create procedure spCreateTable
   as
    begin
       create table testtb(Name varchar(20))
    end

execute it as:-

exec spCreateTable

How to analyze a JMeter summary report?

A Jmeter Test Plan must have listener to showcase the result of performance test execution.

  • Listeners capture the response coming back from Server while Jmeter runs and showcase in the form of – tree, tables, graphs and log files.

  • It also allows you to save the result in a file for future reference. There are many types of listeners Jmeter provides. Some of them are: Summary Report, Aggregate Report, Aggregate Graph, View Results Tree, View Results in Table etc.

Here is the detailed understanding of each parameter in Summary report.

By referring to the figure:

image

Label: It is the name/URL for the specific HTTP(s) Request. If you have selected “Include group name in label?” option then the name of the Thread Group is applied as the prefix to each label.

Samples: This indicates the number of virtual users per request.

Average: It is the average time taken by all the samples to execute specific label. In our case, the average time for Label 1 is 942 milliseconds & total average time is 584 milliseconds.

Min: The shortest time taken by a sample for specific label. If we look at Min value for Label 1 then, out of 20 samples shortest response time one of the sample had was 584 milliseconds.

Max: The longest time taken by a sample for specific label. If we look at Max value for Label 1 then, out of 20 samples longest response time one of the sample had was 2867 milliseconds.

Std. Dev.: This shows the set of exceptional cases which were deviating from the average value of sample response time. The lesser this value more consistent the data. Standard deviation should be less than or equal to half of the average time for a label.

Error%: Percentage of Failed requests per Label.

Throughput: Throughput is the number of request that are processed per time unit(seconds, minutes, hours) by the server. This time is calculated from the start of first sample to the end of the last sample. Larger throughput is better.

KB/Sec: This indicates the amount of data downloaded from server during the performance test execution. In short, it is the Throughput measured in Kilobytes per second.

For more information: http://www.testingjournals.com/understand-summary-report-jmeter/

node.js hash string?

you can use crypto-js javaScript library of crypto standards, there is easiest way to generate sha256 or sha512

const SHA256 = require("crypto-js/sha256");
const SHA512 = require("crypto-js/sha512");

let password = "hello"
let hash_256 = SHA256 (password).toString();
let hash_512 = SHA512 (password).toString();

Remove #N/A in vlookup result

if you are looking to change the colour of the cell in case of vlookup error then go for conditional formatting . To do this go the "CONDITIONAL FORMATTING" > "NEW RULE". In this choose the "Select the rule type" = "Format only cells that contains" . After this the window below changes , in which choose "Error" in the first drop-down .After this proceed accordingly.

How to start jenkins on different port rather than 8080 using command prompt in Windows?

In *nix In CentOS/RedHat

vim /etc/sysconfig/jenkins

# Port Jenkins is listening on.
# Set to -1 to disable
#
JENKINS_PORT="8080"

In windows open XML file C:\Program Files (x86)\Jenkins\jenkins.xml

<executable>%BASE%\jre\bin\java</executable>
  <arguments>-Xrs -Xmx256m -Dhudson.lifecycle=hudson.lifecycle.WindowsServiceLifecycle -jar "%BASE%\jenkins.war" --**httpPort=8083**</arguments>
 i made  above bold  to show you change then 
 <executable>%BASE%\jre\bin\java</executable>
  <arguments>-Xrs -Xmx256m -Dhudson.lifecycle=hudson.lifecycle.WindowsServiceLifecycle -jar "%BASE%\jenkins.war" --httpPort=8083</arguments>

now you have to restart it doesnot work unless you restart http://localhost:8080/restart then after restart http://localhost:8083/ all should be well so looks like the all above response which says it does not work We have restart.

How can I check if a scrollbar is visible?

The solutions provided above will work in the most cases, but checking the scrollHeight and overflow is sometimes not enough and can fail for body and html elements as seen here: https://codepen.io/anon/pen/EvzXZw

1. Solution - Check if the element is scrollable:

function isScrollableY (element) {
  return !!(element.scrollTop || (++element.scrollTop && element.scrollTop--));
}

Note: elements with overflow: hidden are also treated as scrollable (more info), so you might add a condition against that too if needed:

function isScrollableY (element) {
    let style = window.getComputedStyle(element);
    return !!(element.scrollTop || (++element.scrollTop && element.scrollTop--)) 
           && style["overflow"] !== "hidden" && style["overflow-y"] !== "hidden";
}

As far as I know this method only fails if the element has scroll-behavior: smooth.

Explanation: The trick is, that the attempt of scrolling down and reverting it won't be rendered by the browser. The topmost function can also be written like the following:

_x000D_
_x000D_
function isScrollableY (element) {
  // if scrollTop is not 0 / larger than 0, then the element is scrolled and therefore must be scrollable
  // -> true  
  if (element.scrollTop === 0) {
    // if the element is zero it may be scrollable  
    // -> try scrolling about 1 pixel
    element.scrollTop++;
    // if the element is zero then scrolling did not succeed and therefore it is not scrollable 
    // -> false  
    if (element.scrollTop === 0) return false;
    // else the element is scrollable; reset the scrollTop property
    // -> true
    element.scrollTop--;
  }
  return true;
}
_x000D_
_x000D_
_x000D_

2. Solution - Do all the necessary checks:

function isScrollableY (element) {
  const style = window.getComputedStyle(element);
  
  if (element.scrollHeight > element.clientHeight &&
      style["overflow"] !== "hidden" && style["overflow-y"] !== "hidden" &&
      style["overflow"] !== "clip" && style["overflow-y"] !== "clip"
  ) {
    if (element === document.scrollingElement) return true;
    else if (style["overflow"] !== "visible" && style["overflow-y"] !== "visible") {
      // special check for body element (https://drafts.csswg.org/cssom-view/#potentially-scrollable)
      if (element === document.body) {
        const parentStyle = window.getComputedStyle(element.parentElement);
        if (parentStyle["overflow"] !== "visible" && parentStyle["overflow-y"] !== "visible" &&
            parentStyle["overflow"] !== "clip" && parentStyle["overflow-y"] !== "clip"
        ) {
          return true;
        }
      }
      else return true;
    }
  }
  
  return false;
}

Checking if an object is a number in C#

Rather than rolling your own, the most reliable way to tell if an in-built type is numeric is probably to reference Microsoft.VisualBasic and call Information.IsNumeric(object value). The implementation handles a number of subtle cases such as char[] and HEX and OCT strings.

Phone validation regex

/^(([+]{0,1}\d{2})|\d?)[\s-]?[0-9]{2}[\s-]?[0-9]{3}[\s-]?[0-9]{4}$/gm

https://regexr.com/4n3c4

Tested for

+94 77 531 2412

+94775312412

077 531 2412

0775312412

77 531 2412

// Not matching

77-53-12412

+94-77-53-12412

077 123 12345

77123 12345

Saving numpy array to txt file row wise

import numpy as np

a = [1,2,3]    
b = np.array(a).reshape((1,3))    
np.savetxt('a.txt',b,fmt='%d')

Convert python long/int to fixed size byte array

long/int to the byte array looks like exact purpose of struct.pack. For long integers that exceed 4(8) bytes, you can come up with something like the next:

>>> limit = 256*256*256*256 - 1
>>> i = 1234567890987654321
>>> parts = []
>>> while i:
        parts.append(i & limit)
        i >>= 32

>>> struct.pack('>' + 'L'*len(parts), *parts )
'\xb1l\x1c\xb1\x11"\x10\xf4'

>>> struct.unpack('>LL', '\xb1l\x1c\xb1\x11"\x10\xf4')
(2976652465L, 287445236)
>>> (287445236L << 32) + 2976652465L
1234567890987654321L

Javascript Append Child AFTER Element

You can use:

if (parentGuest.nextSibling) {
  parentGuest.parentNode.insertBefore(childGuest, parentGuest.nextSibling);
}
else {
  parentGuest.parentNode.appendChild(childGuest);
}

But as Pavel pointed out, the referenceElement can be null/undefined, and if so, insertBefore behaves just like appendChild. So the following is equivalent to the above:

parentGuest.parentNode.insertBefore(childGuest, parentGuest.nextSibling);

How do I sort a table in Excel if it has cell references in it?

For me this worked like below -

I had sheet name references in formula for the same sheet. When I removed current sheet name from the formula and sorted it worked correctly.

How can I enable the MySQLi extension in PHP 7?

On Ubuntu, when mysqli is missing, execute the following,

sudo apt-get install php7.x-mysqli

sudo service apache2 restart

Replace 7.x with your PHP version.

Note: This could be 7.0 and up, but for example Drupal recommends PHP 7.2 on grounds of security among others.

To check your PHP version, on the command-line type:

php -v

You do exactly the same if you are missing mbstring:

apt-get install php7.x-mbstring

service apache2 restart

I recently had to do this for phpMyAdmin when upgrading PHP from 7.0 to 7.2 on Ubuntu 16.04 (Xenial Xerus).

How can I get all a form's values that would be submitted without submitting

The jquery form plugin offers an easy way to iterate over your form elements and put them in a query string. It might also be useful for whatever else you need to do with these values.

var queryString = $('#myFormId').formSerialize();

From http://malsup.com/jquery/form

Or using straight jquery:

var queryString = $('#myFormId').serialize();

Pseudo-terminal will not be allocated because stdin is not a terminal

All relevant information is in the existing answers, but let me attempt a pragmatic summary:

tl;dr:

  • DO pass the commands to run using a command-line argument:
    ssh jdoe@server '...'

    • '...' strings can span multiple lines, so you can keep your code readable even without the use of a here-document:
      ssh jdoe@server ' ... '
  • Do NOT pass the commands via stdin, as is the case when you use a here-document:
    ssh jdoe@server <<'EOF' # Do NOT do this ... EOF

Passing the commands as an argument works as-is, and:

  • the problem with the pseudo-terminal will not even arise.
  • you won't need an exit statement at the end of your commands, because the session will automatically exit after the commands have been processed.

In short: passing commands via stdin is a mechanism that is at odds with ssh's design and causes problems that must then be worked around.
Read on, if you want to know more.


Optional background information:

ssh's mechanism for accepting commands to execute on the target server is a command-line argument: the final operand (non-option argument) accepts a string containing one or more shell commands.

  • By default, these commands run unattended, in an non-interactive shell, without the use of a (pseudo) terminal (option -T is implied), and the session automatically ends when the last command finishes processing.

  • In the event that your commands require user interaction, such as responding to an interactive prompt, you can explicitly request the creation of a pty (pseudo-tty), a pseudo terminal, that enables interacting with the remote session, using the -t option; e.g.:

    • ssh -t jdoe@server 'read -p "Enter something: "; echo "Entered: [$REPLY]"'

    • Note that the interactive read prompt only works correctly with a pty, so the -t option is needed.

    • Using a pty has a notable side effect: stdout and stderr are combined and both reported via stdout; in other words: you lose the distinction between regular and error output; e.g.:

      • ssh jdoe@server 'echo out; echo err >&2' # OK - stdout and stderr separate

      • ssh -t jdoe@server 'echo out; echo err >&2' # !! stdout + stderr -> stdout

In the absence of this argument, ssh creates an interactive shell - including when you send commands via stdin, which is where the trouble begins:

  • For an interactive shell, ssh normally allocates a pty (pseudo-terminal) by default, except if its stdin is not connected to a (real) terminal.

    • Sending commands via stdin means that ssh's stdin is no longer connected to a terminal, so no pty is created, and ssh warns you accordingly:
      Pseudo-terminal will not be allocated because stdin is not a terminal.

    • Even the -t option, whose express purpose is to request creation of a pty, is not enough in this case: you'll get the same warning.

      • Somewhat curiously, you must then double the -t option to force creation of a pty: ssh -t -t ... or ssh -tt ... shows that you really, really mean it.

      • Perhaps the rationale for requiring this very deliberate step is that things may not work as expected. For instance, on macOS 10.12, the apparent equivalent of the above command, providing the commands via stdin and using -tt, does not work properly; the session gets stuck after responding to the read prompt:
        ssh -tt jdoe@server <<<'read -p "Enter something: "; echo "Entered: [$REPLY]"'


In the unlikely event that the commands you want to pass as an argument make the command line too long for your system (if its length approaches getconf ARG_MAX - see this article), consider copying the code to the remote system in the form of a script first (using, e.g., scp), and then send a command to execute that script.

In a pinch, use -T, and provide the commands via stdin, with a trailing exit command, but note that if you also need interactive features, using -tt in lieu of -T may not work.

How to set up a Web API controller for multipart/form-data

I normally use the HttpPostedFileBase parameter only in Mvc Controllers. When dealing with ApiControllers try checking the HttpContext.Current.Request.Files property for incoming files instead:

[HttpPost]
public string UploadFile()
{
    var file = HttpContext.Current.Request.Files.Count > 0 ?
        HttpContext.Current.Request.Files[0] : null;

    if (file != null && file.ContentLength > 0)
    {
        var fileName = Path.GetFileName(file.FileName);

        var path = Path.Combine(
            HttpContext.Current.Server.MapPath("~/uploads"),
            fileName
        );

        file.SaveAs(path);
    }

    return file != null ? "/uploads/" + file.FileName : null;
}

Spring Boot access static resources missing scr/main/resources

Just use Spring type ClassPathResource.

File file = new ClassPathResource("countries.xml").getFile();

As long as this file is somewhere on classpath Spring will find it. This can be src/main/resources during development and testing. In production, it can be current running directory.

EDIT: This approach doesn't work if file is in fat JAR. In such case you need to use:

InputStream is = new ClassPathResource("countries.xml").getInputStream();

How to make gradient background in android

Visual examples help with this kind of question.

Boilerplate

In order to create a gradient, you create an xml file in res/drawable. I am calling mine my_gradient_drawable.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:type="linear"
        android:angle="0"
        android:startColor="#f6ee19"
        android:endColor="#115ede" />
</shape>

You set it to the background of some view. For example:

<View
    android:layout_width="200dp"
    android:layout_height="100dp"
    android:background="@drawable/my_gradient_drawable"/>

type="linear"

Set the angle for a linear type. It must be a multiple of 45 degrees.

<gradient
    android:type="linear"
    android:angle="0"
    android:startColor="#f6ee19"
    android:endColor="#115ede" />

enter image description here

type="radial"

Set the gradientRadius for a radial type. Using %p means it is a percentage of the smallest dimension of the parent.

<gradient
    android:type="radial"
    android:gradientRadius="10%p"
    android:startColor="#f6ee19"
    android:endColor="#115ede" />

enter image description here

type="sweep"

I don't know why anyone would use a sweep, but I am including it for completeness. I couldn't figure out how to change the angle, so I am only including one image.

<gradient
    android:type="sweep"
    android:startColor="#f6ee19"
    android:endColor="#115ede" />

enter image description here

center

You can also change the center of the sweep or radial types. The values are fractions of the width and height. You can also use %p notation.

android:centerX="0.2"
android:centerY="0.7"

enter image description here

How can I convert an image into Base64 string using JavaScript?

I found that the safest and reliable way to do it is to use FileReader().

Demo: Image to Base64

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
  </head>
  <body>
    <input id="myinput" type="file" onchange="encode();" />
    <div id="dummy">
    </div>
    <div>
      <textarea style="width:100%;height:500px;" id="txt">
      </textarea>
    </div>
    <script>
      function encode() {
        var selectedfile = document.getElementById("myinput").files;
        if (selectedfile.length > 0) {
          var imageFile = selectedfile[0];
          var fileReader = new FileReader();
          fileReader.onload = function(fileLoadedEvent) {
            var srcData = fileLoadedEvent.target.result;
            var newImage = document.createElement('img');
            newImage.src = srcData;
            document.getElementById("dummy").innerHTML = newImage.outerHTML;
            document.getElementById("txt").value = document.getElementById("dummy").innerHTML;
          }
          fileReader.readAsDataURL(imageFile);
        }
      }
    </script>
  </body>
</html>

UPDATE - THE SAME CODE WITH COMMENTS FOR @AnniekJ REQUEST:

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
  </head>
  <body>
    <input id="myinput" type="file" onchange="encode();" />
    <div id="dummy">
    </div>
    <div>
      <textarea style="width:100%;height:500px;" id="txt">
      </textarea>
    </div>
    <script>
      function encode() {
        // Get the file objects that was selected by the user from myinput - a file picker control
        var selectedfile = document.getElementById("myinput").files;
        // Check that the user actually selected file/s from the "file picker" control
        // Note - selectedfile is an array, hence we check it`s length, when length of the array
        // is bigger than 0 than it means the array containes file objects
        if (selectedfile.length > 0) {
          // Set the first file object inside the array to this variable
          // Note: if multiple files are selected we can itterate on all of the selectedfile array  using a for loop - BUT in order to not make this example complicated we only take the first file object that was selected
          var imageFile = selectedfile[0];
          // Set a filereader object to asynchronously read the contents of files (or raw data buffers) stored on the            user's computer, using File or Blob objects to specify the file or data to read. 
          var fileReader = new FileReader();
          // We declare an event of the fileReader class (onload event) and we register an anonimous function that will be executed when the event is raised. it is "trick" we preapare in order for the onload event to be raised after the last line of this code will be executed (fileReader.readAsDataURL(imageFile);) - please read about events in javascript if you are not familiar with "Events" 
          fileReader.onload = function(fileLoadedEvent) {
            // AT THIS STAGE THE EVENT WAS RAISED
            // Here we are getting the file contents - basiccaly the base64 mapping
            var srcData = fileLoadedEvent.target.result;
            // We create an image html element dinamically in order to display the image
            var newImage = document.createElement('img');
            // We set the source of the image we created
            newImage.src = srcData;
            // ANOTHER TRICK TO EXTRACT THE BASE64 STRING
            // We set the outer html of the new image to the div element
            document.getElementById("dummy").innerHTML = newImage.outerHTML;
            // Then we take the inner html of the div and we have the base64 string
            document.getElementById("txt").value = document.getElementById("dummy").innerHTML;
          }
          // This line will raise the fileReader.onload event - note we are passing the file object here as an argument to the function of the event  
          fileReader.readAsDataURL(imageFile);
        }
      }
    </script>
  </body>
</html>

Byte[] to InputStream or OutputStream

we can convert byte[] array into input stream by using ByteArrayInputStream

String str = "Welcome to awesome Java World";
    byte[] content = str.getBytes();
    int size = content.length;
    InputStream is = null;
    byte[] b = new byte[size];
    is = new ByteArrayInputStream(content);

For full example please check here http://www.onlinecodegeek.com/2015/09/how-to-convert-byte-into-inputstream.html

JQUERY: Uncaught Error: Syntax error, unrecognized expression

try

console.log($("#"+d));

your solution is passing the double quotes as part of the string.

How to check if a directory containing a file exist?

To check if a folder exists or not, you can simply use the exists() method:

// Create a File object representing the folder 'A/B'
def folder = new File( 'A/B' )

// If it doesn't exist
if( !folder.exists() ) {
  // Create all folders up-to and including B
  folder.mkdirs()
}

// Then, write to file.txt inside B
new File( folder, 'file.txt' ).withWriterAppend { w ->
  w << "Some text\n"
}

fatal: This operation must be run in a work tree

You repository is bare, i.e. it does not have a working tree attached to it. You can clone it locally to create a working tree for it, or you could use one of several other options to tell Git where the working tree is, e.g. the --work-tree option for single commands, or the GIT_WORK_TREE environment variable. There is also the core.worktree configuration option but it will not work in a bare repository (check the man page for what it does).

# git --work-tree=/path/to/work/tree checkout master
# GIT_WORK_TREE=/path/to/work/tree git status

Convert a list to a data frame

Extending on @Marek's answer: if you want to avoid strings to be turned into factors and efficiency is not a concern try

do.call(rbind, lapply(your_list, data.frame, stringsAsFactors=FALSE))

Unable to resolve dependency for ':app@debug/compileClasspath': Could not resolve

FOR ANYONE GETTING THIS WHEN TRYING TO IMPORT THEIR OWN CREATED LIBRARIES

I have been playing with Kotlin Multiplatform libraries and was trying to publish my libraries using jitpack and then pulling them into other projects. I'm new to most of this and didn't know I needed to add publishLibraryVariants to my android configuration in gradle. I followed other tutorials that didn't require this, so I'm not sure what it is about Kotlin MPP that makes you need it. This is the code though. You could likely publish other variants that met your needs, but these appear to be the standard requirements to build with a basic project. The () after android aren't absolutely necessary, but the default script comes with them so I left it. The code is essentially the same for Kotlin or Groovy DSL.

In the gradle script for the library being published

kotlin {
    android() {
        publishLibraryVariants("release", "debug")
        …
    }
    …
}

Python progression path - From apprentice to guru

Learning algorithms/maths/file IO/Pythonic optimisation

This won't get you guru-hood but to start out, try working through the Project Euler problems The first 50 or so shouldn't tax you if you have decent high-school mathematics and know how to Google. When you solve one you get into the forum where you can look through other people's solutions which will teach you even more. Be decent though and don't post up your solutions as the idea is to encourage people to work it out for themselves.

Forcing yourself to work in Python will be unforgiving if you use brute-force algorithms. This will teach you how to lay out large datasets in memory and access them efficiently with the fast language features such as dictionaries.

From doing this myself I learnt:

  • File IO
  • Algorithms and techniques such as Dynamic Programming
  • Python data layout
    • Dictionaries/hashmaps
    • Lists
    • Tuples
    • Various combinations thereof, e.g. dictionaries to lists of tuples
  • Generators
  • Recursive functions
  • Developing Python libraries
    • Filesystem layout
    • Reloading them during an interpreter session

And also very importantly

  • When to give up and use C or C++!

All of this should be relevant to Bioinformatics

Admittedly I didn't learn about the OOP features of Python from that experience.

Counting the occurrences / frequency of array elements

There is a much better and easy way that we can do this using ramda.js. Code sample here

const ary = [5, 5, 5, 2, 2, 2, 2, 2, 9, 4]; R.countBy(r=> r)(ary) countBy documentation is at documentation

PHP - find entry by object property from an array of objects

I posted what I use to solve this very issue efficiently here using a quick Binary Search Algorithm: https://stackoverflow.com/a/52786742/1678210

I didn't want to copy the same answer. Someone else had asked it slightly differently but the answer is the same.

Get Unix timestamp with C++

The most common advice is wrong, you can't just rely on time(). That's used for relative timing: ISO C++ doesn't specify that 1970-01-01T00:00Z is time_t(0)

What's worse is that you can't easily figure it out, either. Sure, you can find the calendar date of time_t(0) with gmtime, but what are you going to do if that's 2000-01-01T00:00Z ? How many seconds were there between 1970-01-01T00:00Z and 2000-01-01T00:00Z? It's certainly no multiple of 60, due to leap seconds.

AutoComplete TextBox Control

    You can add a parameter in the query like @emailadd to be added in the aspx.cs file where the Stored Procedure is called with cmd.Parameter.AddWithValue.
    The trick is that the @emailadd parameter doesn't exist in the table design of the select query, but being added and inserted in the table.

    USE [DRDOULATINSTITUTE]
    GO
    /****** Object:  StoredProcedure [dbo].[ReikiInsertRow]    Script Date: 5/18/2016 11:12:33 AM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    ALTER procedure [dbo].[ReikiInsertRow]
    @Reiki varchar(100),
    @emailadd varchar(50)
    as
    insert into dbo.ReikiPowerDisplay
    select Reiki,ReikiDescription, @emailadd from ReikiPower
    where Reiki=@Reiki;

Posted By: Aneel Goplani. CIS. 2002. USA

What is the significance of #pragma marks? Why do we need #pragma marks?

In simple word we can say that #pragma mark - is used for categorizing methods, so you can find your methods easily. It is very useful for long projects.

sql set variable using COUNT

You can select directly into the variable rather than using set:

DECLARE @times int

SELECT @times = COUNT(DidWin)
FROM thetable
WHERE DidWin = 1 AND Playername='Me'

If you need to set multiple variables you can do it from the same select (example a bit contrived):

DECLARE @wins int, @losses int

SELECT @wins = SUM(DidWin), @losses = SUM(DidLose)
FROM thetable
WHERE Playername='Me'

If you are partial to using set, you can use parentheses:

DECLARE @wins int, @losses int

SET (@wins, @losses) = (SELECT SUM(DidWin), SUM(DidLose)
FROM thetable
WHERE Playername='Me');

How do I get TimeSpan in minutes given two Dates?

TimeSpan span = end-start;
double totalMinutes = span.TotalMinutes;

How to get parameters from the URL with JSP

Use EL (JSP Expression Language):

${param.accountID}

using nth-child in tables tr td

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

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

Detect URLs in text with JavaScript

Generic Object Oriented Solution

For people like me that use frameworks like angular that don't allow manipulating DOM directly, I created a function that takes a string and returns an array of url/plainText objects that can be used to create any UI representation that you want.

URL regex

For URL matching I used (slightly adapted) h0mayun regex: /(?:(?:https?:\/\/)|(?:www\.))[^\s]+/g

My function also drops punctuation characters from the end of a URL like . and , that I believe more often will be actual punctuation than a legit URL ending (but it could be! This is not rigorous science as other answers explain well) For that I apply the following regex onto matched URLs /^(.+?)([.,?!'"]*)$/.

Typescript code

    export function urlMatcherInText(inputString: string): UrlMatcherResult[] {
        if (! inputString) return [];

        const results: UrlMatcherResult[] = [];

        function addText(text: string) {
            if (! text) return;

            const result = new UrlMatcherResult();
            result.type = 'text';
            result.value = text;
            results.push(result);
        }

        function addUrl(url: string) {
            if (! url) return;

            const result = new UrlMatcherResult();
            result.type = 'url';
            result.value = url;
            results.push(result);
        }

        const findUrlRegex = /(?:(?:https?:\/\/)|(?:www\.))[^\s]+/g;
        const cleanUrlRegex = /^(.+?)([.,?!'"]*)$/;

        let match: RegExpExecArray;
        let indexOfStartOfString = 0;

        do {
            match = findUrlRegex.exec(inputString);

            if (match) {
                const text = inputString.substr(indexOfStartOfString, match.index - indexOfStartOfString);
                addText(text);

                var dirtyUrl = match[0];
                var urlDirtyMatch = cleanUrlRegex.exec(dirtyUrl);
                addUrl(urlDirtyMatch[1]);
                addText(urlDirtyMatch[2]);

                indexOfStartOfString = match.index + dirtyUrl.length;
            }
        }
        while (match);

        const remainingText = inputString.substr(indexOfStartOfString, inputString.length - indexOfStartOfString);
        addText(remainingText);

        return results;
    }

    export class UrlMatcherResult {
        public type: 'url' | 'text'
        public value: string
    }

How Do I Insert a Byte[] Into an SQL Server VARBINARY Column

No problem if all the arrays you are about to use in this scenario are small like in your example.

If you will use this for large blobs (e.g. storing large binary files many Mbs or even Gbs in size into a VARBINARY) then you'd probably be much better off using specific support in SQL Server for reading/writing subsections of such large blobs. Things like READTEXT and UPDATETEXT, or in current versions of SQL Server SUBSTRING.

For more information and examples see either my 2006 article in .NET Magazine ("BLOB + Stream = BlobStream", in Dutch, with complete source code), or an English translation and generalization of this on CodeProject by Peter de Jonghe. Both of these are linked from my weblog.

Bootstrap modal in React.js

getDOMNode() is deprecated. Instead use ref to access DOM element. Here is working Modal component (Bootstrap 4). Decide whether to show or not to show Modal component in parent component.

Example: https://jsfiddle.net/sqfhkdcy/

class Modal extends Component {
    constructor(props) {
        super(props);
    }
    componentDidMount() {
        $(this.modal).modal('show');
        $(this.modal).on('hidden.bs.modal', handleModalCloseClick);
    }
    render() {
        return (
            <div>
                <div className="modal fade" ref={modal=> this.modal = modal} id="exampleModal" tabIndex="-1" role="dialog" aria- labelledby="exampleModalLabel" aria-hidden="true">
                    <div className="modal-dialog" role="document">
                        <div className="modal-content">
                            <div className="modal-header">
                                <h5 className="modal-title" id="exampleModalLabel">Modal title
                                </h5>
                                <button type="button" className="close" data- dismiss="modal" aria-label="Close">
                                    <span aria-hidden="true">&times;</span>
                                </button>
                            </div>
                            <div className="modal-body">
                                ...
                            </div>
                            <div className="modal-footer">
                                <button type="button" className="btn btn-secondary" data- dismiss="modal">Close</button>
                                <button type="button" className="btn btn-primary">Save changes</button>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        );
    }
}

Edit:

Here are the necessary imports to make it work:

import $ from 'jquery';
window.jQuery = $;
window.$ = $;
global.jQuery = $;

Not Equal to This OR That in Lua

Your problem stems from a misunderstanding of the or operator that is common to people learning programming languages like this. Yes, your immediate problem can be solved by writing x ~= 0 and x ~= 1, but I'll go into a little more detail about why your attempted solution doesn't work.

When you read x ~=(0 or 1) or x ~= 0 or 1 it's natural to parse this as you would the sentence "x is not equal to zero or one". In the ordinary understanding of that statement, "x" is the subject, "is not equal to" is the predicate or verb phrase, and "zero or one" is the object, a set of possibilities joined by a conjunction. You apply the subject with the verb to each item in the set.

However, Lua does not parse this based on the rules of English grammar, it parses it in binary comparisons of two elements based on its order of operations. Each operator has a precedence which determines the order in which it will be evaluated. or has a lower precedence than ~=, just as addition in mathematics has a lower precedence than multiplication. Everything has a lower precedence than parentheses.

As a result, when evaluating x ~=(0 or 1), the interpreter will first compute 0 or 1 (because of the parentheses) and then x ~= the result of the first computation, and in the second example, it will compute x ~= 0 and then apply the result of that computation to or 1.

The logical operator or "returns its first argument if this value is different from nil and false; otherwise, or returns its second argument". The relational operator ~= is the inverse of the equality operator ==; it returns true if its arguments are different types (x is a number, right?), and otherwise compares its arguments normally.

Using these rules, x ~=(0 or 1) will decompose to x ~= 0 (after applying the or operator) and this will return 'true' if x is anything other than 0, including 1, which is undesirable. The other form, x ~= 0 or 1 will first evaluate x ~= 0 (which may return true or false, depending on the value of x). Then, it will decompose to one of false or 1 or true or 1. In the first case, the statement will return 1, and in the second case, the statement will return true. Because control structures in Lua only consider nil and false to be false, and anything else to be true, this will always enter the if statement, which is not what you want either.

There is no way that you can use binary operators like those provided in programming languages to compare a single variable to a list of values. Instead, you need to compare the variable to each value one by one. There are a few ways to do this. The simplest way is to use De Morgan's laws to express the statement 'not one or zero' (which can't be evaluated with binary operators) as 'not one and not zero', which can trivially be written with binary operators:

if x ~= 1 and x ~= 0 then
    print( "X must be equal to 1 or 0" )
    return
end

Alternatively, you can use a loop to check these values:

local x_is_ok = false
for i = 0,1 do 
    if x == i then
        x_is_ok = true
    end
end
if not x_is_ok then
    print( "X must be equal to 1 or 0" )
    return
end

Finally, you could use relational operators to check a range and then test that x was an integer in the range (you don't want 0.5, right?)

if not (x >= 0 and x <= 1 and math.floor(x) == x) then
    print( "X must be equal to 1 or 0" )
    return
end

Note that I wrote x >= 0 and x <= 1. If you understood the above explanation, you should now be able to explain why I didn't write 0 <= x <= 1, and what this erroneous expression would return!

Run Excel Macro from Outside Excel Using VBScript From Command Line

Since my related question was removed by a righteous hand after I had killed the whole day searching how to beat the "macro not found or disabled" error, posting here the only syntax that worked for me (application.run didn't, no matter what I tried)

Set objExcel = CreateObject("Excel.Application")

' Didn't run this way from the Modules
'objExcel.Application.Run "c:\app\Book1.xlsm!Sub1"
' Didn't run this way either from the Sheet
'objExcel.Application.Run "c:\app\Book1.xlsm!Sheet1.Sub1"
' Nor did it run from a named Sheet
'objExcel.Application.Run "c:\app\Book1.xlsm!Named_Sheet.Sub1"

' Only ran like this (from the Module1)

Set objWorkbook = objExcel.Workbooks.Open("c:\app\Book1.xlsm")
objExcel.Run "Sub1"

Excel 2010, Win 7

Iterate over object attributes in python

For all the pythonian zealots out there I'm sure Johan Cleeze would approve of your dogmatism ;). I'm leaving this answer keep demeriting it It actually makes me more confidant. Leave a comment you chickens!

For python 3.6

class SomeClass:

    def attr_list1(self, should_print=False):

        for k in self.__dict__.keys():
            v = self.__dict__.__getitem__(k)
            if should_print:
                print(f"attr: {k}    value: {v}")

    def attr_list(self, should_print=False):

        b = [(k, v) for k, v in self.__dict__.items()]
        if should_print:
            [print(f"attr: {a[0]}    value: {a[1]}") for a in b]
        return b

With MySQL, how can I generate a column containing the record index in a table?

If you just want to know the position of one specific user after order by field score, you can simply select all row from your table where field score is higher than the current user score. And use row number returned + 1 to know which position of this current user.

Assuming that your table is league_girl and your primary field is id, you can use this:

SELECT count(id) + 1 as rank from league_girl where score > <your_user_score>

Cookies on localhost with explicit domain

Results I had varied by browser.

Chrome- 127.0.0.1 worked but localhost .localhost and "" did not. Firefox- .localhost worked but localhost, 127.0.0.1, and "" did not.

Have not tested in Opera, IE, or Safari

Databound drop down list - initial value

I know this is old, but a combination of these ideas leads to a very elegant solution:

Keep all the default property settings for the DropDownList (AppendDataBoundItems=false, Items empty). Then handle the DataBound event like this:

protected void dropdown_DataBound(object sender, EventArgs e)
{
    DropDownList list = sender as DropDownList;
    if (list != null)
        list.Items.Insert(0, "--Select One--");
}

The icing on the cake is that this one handler can be shared by any number of DropDownList objects, or even put into a general-purpose utility library for all your projects.

Curl command line for consuming webServices?

If you want a fluffier interface than the terminal, http://hurl.it/ is awesome.

Return Index of an Element in an Array Excel VBA

array of variants:

    Public Function GetIndex(ByRef iaList() As Variant, ByVal value As Variant) As Long

    Dim i As Long

     For i = LBound(iaList) To UBound(iaList)
      If value = iaList(i) Then
       GetIndex = i
       Exit For
      End If
     Next i

    End Function

a fastest version for integers (as pref tested below)

    Public Function GetIndex(ByRef iaList() As Integer, ByVal value As Integer) As Integer
     Dim i As Integer

     For i = LBound(iaList) To UBound(iaList)
      If iaList(i) = value Then: GetIndex = i: Exit For:
     Next i

    End Function

' a snippet, replace myList and myValue to your varible names: (also have not tested)

a snippet, lets test the assumption the passing by reference as argument means something. (the answer is no) to use it replace myList and myValue to your variable names:

  Dim found As Integer, foundi As Integer ' put only once
  found = -1
  For foundi = LBound(myList) To UBound(myList):
   If myList(foundi) = myValue Then
    found = foundi: Exit For
   End If
  Next
  result = found

to prove the point I have made some benchmarks

here are the results:

---------------------------
Milliseconds
---------------------------
result0: 5 ' just empty loop

result1: 2702  ' function variant array

result2: 1498  ' function integer array

result3: 2511 ' snippet variant array

result4: 1508 ' snippet integer array

result5: 58493 ' excel function Application.Match on variant array

result6: 136128 ' excel function Application.Match on integer array
---------------------------
OK   
---------------------------

a module:

Public Declare Function GetTickCount Lib "kernel32.dll" () As Long
#If VBA7 Then
    Public Declare PtrSafe Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As LongPtr) 'For 64 Bit Systems
#Else
    Public Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long) 'For 32 Bit Systems
#End If

    Public Function GetIndex1(ByRef iaList() As Variant, ByVal value As Variant) As Long

    Dim i As Long

     For i = LBound(iaList) To UBound(iaList)
      If value = iaList(i) Then
       GetIndex = i
       Exit For
      End If
     Next i

    End Function


'maybe a faster variant for integers

    Public Function GetIndex2(ByRef iaList() As Integer, ByVal value As Integer) As Integer
     Dim i As Integer

     For i = LBound(iaList) To UBound(iaList)
      If iaList(i) = value Then: GetIndex = i: Exit For:
     Next i

    End Function

' a snippet, replace myList and myValue to your varible names: (also have not tested)



    Public Sub test1()
     Dim i As Integer

     For i = LBound(iaList) To UBound(iaList)
      If iaList(i) = value Then: GetIndex = i: Exit For:
     Next i

    End Sub


Sub testTimer()

Dim myList(500) As Variant, myValue As Variant
Dim myList2(500) As Integer, myValue2 As Integer
Dim n

For n = 1 To 500
myList(n) = n
Next

For n = 1 To 500
myList2(n) = n
Next

myValue = 100
myValue2 = 100


Dim oPM
Set oPM = New PerformanceMonitor
Dim result0 As Long
Dim result1 As Long
Dim result2 As Long
Dim result3 As Long
Dim result4 As Long
Dim result5 As Long
Dim result6 As Long

Dim t As Long

Dim a As Long

a = 0
Dim i
't = GetTickCount
oPM.StartCounter
For i = 1 To 1000000

Next
result0 = oPM.TimeElapsed() '  GetTickCount - t

a = 0

't = GetTickCount
oPM.StartCounter
For i = 1 To 1000000
a = GetIndex1(myList, myValue)
Next
result1 = oPM.TimeElapsed()
'result1 = GetTickCount - t


a = 0

't = GetTickCount
oPM.StartCounter
For i = 1 To 1000000
a = GetIndex2(myList2, myValue2)
Next
result2 = oPM.TimeElapsed()
'result2 = GetTickCount - t



a = 0

't = GetTickCount

oPM.StartCounter
Dim found As Integer, foundi As Integer ' put only once
For i = 1 To 1000000
found = -1
For foundi = LBound(myList) To UBound(myList):
 If myList(foundi) = myValue Then
  found = foundi: Exit For
 End If
Next
a = found
Next
result3 = oPM.TimeElapsed()
'result3 = GetTickCount - t



a = 0

't = GetTickCount

oPM.StartCounter
For i = 1 To 1000000
found = -1
For foundi = LBound(myList2) To UBound(myList2):
 If myList2(foundi) = myValue2 Then
  found = foundi: Exit For
 End If
Next
a = found
Next
result4 = oPM.TimeElapsed()
'result4 = GetTickCount - t


a = 0

't = GetTickCount
oPM.StartCounter
For i = 1 To 1000000
a = pos = Application.Match(myValue, myList, False)
Next
result5 = oPM.TimeElapsed()
'result5 = GetTickCount - t



a = 0

't = GetTickCount
oPM.StartCounter
For i = 1 To 1000000
a = pos = Application.Match(myValue2, myList2, False)
Next
result6 = oPM.TimeElapsed()
'result6 = GetTickCount - t


MsgBox "result0: " & result0 & vbCrLf & "result1: " & result1 & vbCrLf & "result2: " & result2 & vbCrLf & "result3: " & result3 & vbCrLf & "result4: " & result4 & vbCrLf & "result5: " & result5 & vbCrLf & "result6: " & result6, , "Milliseconds"
End Sub

a class named PerformanceMonitor

Option Explicit

Private Type LARGE_INTEGER
    lowpart As Long
    highpart As Long
End Type

Private Declare Function QueryPerformanceCounter Lib "kernel32" (lpPerformanceCount As LARGE_INTEGER) As Long
Private Declare Function QueryPerformanceFrequency Lib "kernel32" (lpFrequency As LARGE_INTEGER) As Long

Private m_CounterStart As LARGE_INTEGER
Private m_CounterEnd As LARGE_INTEGER
Private m_crFrequency As Double

Private Const TWO_32 = 4294967296# ' = 256# * 256# * 256# * 256#

Private Function LI2Double(LI As LARGE_INTEGER) As Double
Dim Low As Double
    Low = LI.lowpart
    If Low < 0 Then
        Low = Low + TWO_32
    End If
    LI2Double = LI.highpart * TWO_32 + Low
End Function

Private Sub Class_Initialize()
Dim PerfFrequency As LARGE_INTEGER
    QueryPerformanceFrequency PerfFrequency
    m_crFrequency = LI2Double(PerfFrequency)
End Sub

Public Sub StartCounter()
    QueryPerformanceCounter m_CounterStart
End Sub

Property Get TimeElapsed() As Double
Dim crStart As Double
Dim crStop As Double
    QueryPerformanceCounter m_CounterEnd
    crStart = LI2Double(m_CounterStart)
    crStop = LI2Double(m_CounterEnd)
    TimeElapsed = 1000# * (crStop - crStart) / m_crFrequency
End Property

Query an object array using linq

Add:

using System.Linq;

to the top of your file.

And then:

Car[] carList = ...
var carMake = 
    from item in carList
    where item.Model == "bmw" 
    select item.Make;

or if you prefer the fluent syntax:

var carMake = carList
    .Where(item => item.Model == "bmw")
    .Select(item => item.Make);

Things to pay attention to:

  • The usage of item.Make in the select clause instead if s.Make as in your code.
  • You have a whitespace between item and .Model in your where clause

What is boilerplate code?

Boilerplate definition is becoming more global in many other programming languages nowadays. It comes from OOP and hybrid languages that have become OOP and were before procedual have now the same goal to keep repeating the code you build with a model/template/class/object hence why they adapt this term. You make a template and the only things you do for each instance of a template are the parameters to individualize an object this part is what we call boilerplate. You simply re-use the code you made a template of, just with different parameters.

Synonyms
a blueprint is a boilerplate
a stencil is a boilerplate
a footer is a boilerplate
a design pattern for multiple use is a boilerplate
a signature of a mail is a boilerplate

how to get the one entry from hashmap without iterating

Why do you want to avoid calling entrySet() it does not generally create an entirely new object with its own context, but instead just provide a facade object. Simply speaking entrySet() is a pretty cheap operation.

How can I change the font-size of a select option?

We need a trick here...

Normal select-dropdown things won't accept styles. BUT. If there's a "size" parameter in the tag, almost any CSS will apply. With this in mind, I've created a fiddle that's practically equivalent to a normal select tag, plus the value can be edited manually like a ComboBox in visual languages (unless you put readonly in the input tag).

A simplified example:

<style>

    /* only these 2 lines are truly required */
    .stylish span {position:relative;}
    .stylish select {position:absolute;left:0px;display:none}

    /* now you can style the hell out of them */
    .stylish input    { ... }
    .stylish select   { ... }
    .stylish option   { ... }
    .stylish optgroup { ... }

</style>
...
<div class="stylish">
    <label> Choose your superhero: </label>
    <span>
        <input onclick="$(this).closest('div').find('select').slideToggle(110)">
        <br>
        <select size=15 onclick="$(this).hide().closest('div').find('input').val($(this).find('option:selected').text());">

            <optgroup label="Fantasy"></optgroup>
            <option value="gandalf">Gandalf</option>
            <option value="harry">Harry Potter</option>
            <option value="jon">Jon Snow</option>

            <optgroup label="Comics"></optgroup>
            <option value="tony">Tony Stark</option>
            <option value="steve">Steven Rogers</option>
            <option value="natasha">Natasha Romanova</option>

        </select>
    </span>
    <!--

        For the sake of simplicity, I used jQuery here.
        Today it's easy to do the same without it, now
        that we have querySelector(), closest(), etc.

    -->
</div>

A live example:

https://jsfiddle.net/7ac9us70/1052/

Note 1: Sorry for the gradients & all fancy stuff, no they're not necessary, yes I'm showing off, I know, hashtag onlyhuman, hashtag notproud.

Note 2: Those <optgroup> tags don't encapsulate the options belonging under them as they normally should; this is intentional. It's better for the styling (the well-mannered way would be a lot less stylable), and yes this is painless and works in every browser.

How do I iterate through lines in an external file with shell?

One way would be:

while read NAME
do
    echo "$NAME"
done < names.txt

EDIT: Note that the loop gets executed in a sub-shell, so any modified variables will be local, except if you declare them with declare outside the loop.

Dennis Williamson is right. Sorry, must have used piped constructs too often and got confused.

<script> tag vs <script type = 'text/javascript'> tag

<script> is HTML 5.

<script type='text/javascript'> is HTML 4.x (and XHTML 1.x).

<script language="javascript"> is HTML 3.2.

Is it different for different webservers?

No.

when I did an offline javascript test, i realised that i need the <script type = 'text/javascript'> tag.

That isn't the case. Something else must have been wrong with your test case.

usr/bin/ld: cannot find -l<nameOfTheLibrary>

During compilation with g++ via make define LIBRARY_PATH if it may not be appropriate to change the Makefile with the -Loption. I had put my extra library in /opt/lib so I did:

$ export LIBRARY_PATH=/opt/lib/

and then ran make for successful compilation and linking.

To run the program with a shared library define:

$ export LD_LIBRARY_PATH=/opt/lib/

before executing the program.

How to allow remote access to my WAMP server for Mobile(Android)

I assume you are using windows. Open the command prompt and type ipconfig and find out your local address (on your pc) it should look something like 192.168.1.13 or 192.168.0.5 where the end digit is the one that changes. It should be next to IPv4 Address.

If your WAMP does not use virtual hosts the next step is to enter that IP address on your phones browser ie http://192.168.1.13 If you have a virtual host then you will need root to edit the hosts file.

If you want to test the responsiveness / mobile design of your website you can change your user agent in chrome or other browsers to mimic a mobile.

See http://googlesystem.blogspot.co.uk/2011/12/changing-user-agent-new-google-chrome.html.

Edit: Chrome dev tools now has a mobile debug tool where you can change the size of the viewport, spoof user agents, connections (4G, 3G etc).

If you get forbidden access then see this question WAMP error: Forbidden You don't have permission to access /phpmyadmin/ on this server. Basically, change the occurrances of deny,allow to allow,deny in the httpd.conf file. You can access this by the WAMP menu.

To eliminate possible causes of the issue for now set your config file to

<Directory />
    Options FollowSymLinks
    AllowOverride All
    Order allow,deny
    Allow from all
    <RequireAll>
        Require all granted
    </RequireAll>
</Directory>

As thatis working for my windows PC, if you have the directory config block as well change that also to allow all.

Config file that fixed the problem:

https://gist.github.com/samvaughton/6790739

Problem was that the /www apache directory config block still had deny set as default and only allowed from localhost.

mysql query result in php variable

Of course there is. Check out mysql_query, and mysql_fetch_row if you use MySQL.
Example from PHP manual:

<?php
$result = mysql_query("SELECT id,email FROM people WHERE id = '42'");
if (!$result) {
    echo 'Could not run query: ' . mysql_error();
    exit;
}
$row = mysql_fetch_row($result);

echo $row[0]; // 42
echo $row[1]; // the email value
?>

Non-Static method cannot be referenced from a static context with methods and variables

You need to make both your method - printMenu() and getUserChoice() static, as you are directly invoking them from your static main method, without creating an instance of the class, those methods are defined in. And you cannot invoke a non-static method without any reference to an instance of the class they are defined in.

Alternatively you can change the method invocation part to:

BookStoreApp2 bookStoreApp = new BookStoreApp2();
bookStoreApp.printMenu();
bookStoreApp.getUserChoice();

Show pop-ups the most elegant way

See http://adamalbrecht.com/2013/12/12/creating-a-simple-modal-dialog-directive-in-angular-js/ for a simple way of doing modal dialog with Angular and without needing bootstrap

Edit: I've since been using ng-dialog from http://likeastore.github.io/ngDialog which is flexible and doesn't have any dependencies.

What in layman's terms is a Recursive Function using PHP

Recursion used for Kaprekar's constant

function KaprekarsConstant($num, $count = 1) {
    $input = str_split($num);
    sort($input);

    $ascendingInput  = implode($input);
    $descendingInput = implode(array_reverse($input));

    $result = $ascendingInput > $descendingInput 
        ? $ascendingInput - $descendingInput 
        : $descendingInput - $ascendingInput;

    if ($result != 6174) {
        return KaprekarsConstant(sprintf('%04d', $result), $count + 1);
    }

    return $count;

}

The function keeps calling itself with the result of the calculation until it reaches Kaprekars constant, at which it will return the amount of times the calculations was made.

/edit For anyone that doesn't know Kaprekars Constant, it needs an input of 4 digits with at least two distinct digits.

Right to Left support for Twitter Bootstrap 3

in every version of bootstrap,you can do it manually

  1. set rtl direction to your body
  2. in bootstrap.css file, look for ".col-sm-9{float:left}" expression,change it to float:right

this do most things that you want for rtl

ImportError: No module named pip

I think none of these answers above can fix your problem.

I was also confused by this problem once. You should manually install pip following the official guide pip installation (which currently involves running a single get-pip.py Python script)

after that, just sudo pip install Django. The error will be gone.

npm WARN enoent ENOENT: no such file or directory, open 'C:\Users\Nuwanst\package.json'

Have you created a package.json file? Maybe run this command first again.

C:\Users\Nuwanst\Documents\NodeJS\3.chat>npm init

It creates a package.json file in your folder.

Then run,

C:\Users\Nuwanst\Documents\NodeJS\3.chat>npm install socket.io --save

The --save ensures your module is saved as a dependency in your package.json file.

Let me know if this works.

login to remote using "mstsc /admin" with password

It became a popular question and I got a notification. I am sorry, I forgot to answer before which I should have done. I solved it long back.

net use \\10.100.110.120\C$ MyPassword /user:domain\username /persistent:Yes

Run it in a batch file and you should get what you are looking for.

No shadow by default on Toolbar?

i added

<android.support.v7.widget.Toolbar
...
android:translationZ="5dp"/>

in toolbar description and it works for me. Using 5.0+

Embed Google Map code in HTML with marker

The element that you posted looks like it's just copy-pasted from the Google Maps embed feature.

If you'd like to drop markers for the locations that you have, you'll need to write some JavaScript to do so. I'm learning how to do this as well.

Check out the following: https://developers.google.com/maps/documentation/javascript/overlays

It has several examples and code samples that can be easily re-used and adapted to fit your current problem.

How do I parse JSON from a Java HTTPResponse?

Jackson appears to support some amount of JSON parsing straight from an InputStream. My understanding is that it runs on Android and is fairly quick. On the other hand, it is an extra JAR to include with your app, increasing download and on-flash size.

How to Ping External IP from Java Android

Use this Code: this method works on 4.3+ and also for below versions too.

   try {

         Process process = null;

        if(Build.VERSION.SDK_INT <= 16) {
            // shiny APIS 
               process = Runtime.getRuntime().exec(
                    "/system/bin/ping -w 1 -c 1 " + url);


        } 
        else 
        {

                   process = new ProcessBuilder()
                 .command("/system/bin/ping", url)
                 .redirectErrorStream(true)
                 .start();

            }



        BufferedReader reader = new BufferedReader(new InputStreamReader(
                process.getInputStream()));

        StringBuffer output = new StringBuffer();
        String temp;

        while ( (temp = reader.readLine()) != null)//.read(buffer)) > 0)
        {
            output.append(temp);
            count++;
        }

        reader.close();


        if(count > 0)
            str = output.toString();

        process.destroy();
     } catch (IOException e) {
         e.printStackTrace();
    }

    Log.i("PING Count", ""+count);
    Log.i("PING String", str);

Hashmap holding different data types as values for instance Integer, String and Object

If you don't have Your own Data Class, then you can design your map as follows

Map<Integer, Object> map=new HashMap<Integer, Object>();

Here don't forget to use "instanceof" operator while retrieving the values from MAP.

If you have your own Data class then then you can design your map as follows

Map<Integer, YourClassName> map=new HashMap<Integer, YourClassName>();

import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;


public class HashMapTest {
public static void main(String[] args) {
    Map<Integer,Demo> map=new HashMap<Integer, Demo>();
    Demo d1= new Demo(1,"hi",new Date(),1,1);
    Demo d2= new Demo(2,"this",new Date(),2,1);
    Demo d3= new Demo(3,"is",new Date(),3,1);
    Demo d4= new Demo(4,"mytest",new Date(),4,1);
    //adding values to map
    map.put(d1.getKey(), d1);
    map.put(d2.getKey(), d2);
    map.put(d3.getKey(), d3);
    map.put(d4.getKey(), d4);
    //retrieving values from map
    Set<Integer> keySet= map.keySet();
    for(int i:keySet){
        System.out.println(map.get(i));
    }
    //searching key on map
    System.out.println(map.containsKey(d1.getKey()));
    //searching value on map
    System.out.println(map.containsValue(d1));
}

}
class Demo{
    private int key;
    private String message;
    private Date time;
    private int count;
    private int version;

    public Demo(int key,String message, Date time, int count, int version){
        this.key=key;
        this.message = message;
        this.time = time;
        this.count = count;
        this.version = version;
    }
    public String getMessage() {
        return message;
    }
    public Date getTime() {
        return time;
    }
    public int getCount() {
        return count;
    }
    public int getVersion() {
        return version;
    }
    public int getKey() {
        return key;
    }
    @Override
    public String toString() {
        return "Demo [message=" + message + ", time=" + time
                + ", count=" + count + ", version=" + version + "]";
    }

}

How to declare or mark a Java method as deprecated?

Use the annotation @Deprecated for your method, and you should also mention it in your javadocs.

Better way to right align text in HTML Table

To answer your question directly: no. There is no more simple way to get a consistent look and feel across all modern browsers, without repeating the class on the column. (Although, see below re: nth-child.)

The following is the most efficient way to do this.

HTML:

<table class="products">
  <tr>
    <td>...</td>
    <td>...</td>
    <td class="price">10.00</td>
    <td>...</td>
    <td>...</td>
  </tr>
  <tr>
    <td>...</td>
    <td>...</td>
    <td class="price">11.45</td>
    <td>...</td>
    <td>...</td>
  </tr>
</table>

CSS:

table.products td.price {
  text-align: right;
}

nth-child is now supported by 96% of the browsers, what is below is now 11 years old!

Why you shouldn't use nth-child:

The CSS3 pseudo-selector, nth-child, would be perfect for this -- and much more efficient -- but it is impractical for use on the actual web as it exists today. It is not supported by several major modern browsers, including all IE's from 6-8. Unfortunately, this means that nth-child is unsupported in a significant share (at least 40%) of browsers today.

So, nth-child is awesome, but if you want a consistent look and feel, it's just not feasible to use.

Beginner Python Practice?

You may want to take a look at Pyschools, the website has quite a lot of practice questions on Python Programming.

Flutter: Setting the height of the AppBar

At the time of writing this, I was not aware of PreferredSize. Cinn's answer is better to achieve this.

You can create your own custom widget with a custom height:

import "package:flutter/material.dart";

class Page extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Column(children : <Widget>[new CustomAppBar("Custom App Bar"), new Container()],);
  }
}


class CustomAppBar extends StatelessWidget {

  final String title;
  final double barHeight = 50.0; // change this for different heights 

  CustomAppBar(this.title);

  @override
  Widget build(BuildContext context) {
    final double statusbarHeight = MediaQuery
        .of(context)
        .padding
        .top;

    return new Container(
      padding: new EdgeInsets.only(top: statusbarHeight),
      height: statusbarHeight + barHeight,
      child: new Center(
        child: new Text(
          title,
          style: new TextStyle(fontSize: 20.0, fontWeight: FontWeight.bold),
        ),
      ),
    );
  }
}

Build error: You must add a reference to System.Runtime

The only way that worked for me - add the assembly to web.config

<compilation debug="true" targetFramework="4.5">
  <assemblies>     
    <add assembly="System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />   
  </assemblies>
</compilation>

What is the size of column of int(11) in mysql in bytes?

INT(x) will make difference only in term of display, that is to show the number in x digits, and not restricted to 11. You pair it using ZEROFILL, which will prepend the zeros until it matches your length.

So, for any number of x in INT(x)

  • if the stored value has less digits than x, ZEROFILL will prepend zeros.

INT(5) ZEROFILL with the stored value of 32 will show 00032
INT(5) with the stored value of 32 will show 32
INT with the stored value of 32 will show 32

  • if the stored value has more digits than x, it will be shown as it is.

INT(3) ZEROFILL with the stored value of 250000 will show 250000
INT(3) with the stored value of 250000 will show 250000
INT with the stored value of 250000 will show 250000

The actual value stored in database is not affected, the size is still the same, and any calculation will behave normally.

This also applies to BIGINT, MEDIUMINT, SMALLINT, and TINYINT.

Generate random number between two numbers in JavaScript

to return 1-6 like a dice basically,

return Math.round(Math.random() * 5 + 1);

How to get DATE from DATETIME Column in SQL?

use the following

select sum(transaction_amount) from TransactionMaste
where Card_No = '123' and transaction_date = CONVERT(VARCHAR(10),GETDATE(),111)

or the following

select sum(transaction_amount) from TransactionMaste
where Card_No = '123' and transaction_date = CONVERT(VARCHAR(10), GETDATE(), 120)

How to return multiple objects from a Java method?

As I see it there are really three choices here and the solution depends on the context. You can choose to implement the construction of the name in the method that produces the list. This is the choice you've chosen, but I don't think it is the best one. You are creating a coupling in the producer method to the consuming method that doesn't need to exist. Other callers may not need the extra information and you would be calculating extra information for these callers.

Alternatively, you could have the calling method calculate the name. If there is only one caller that needs this information, you can stop there. You have no extra dependencies and while there is a little extra calculation involved, you've avoided making your construction method too specific. This is a good trade-off.

Lastly, you could have the list itself be responsible for creating the name. This is the route I would go if the calculation needs to be done by more than one caller. I think this puts the responsibility for the creation of the names with the class that is most closely related to the objects themselves.

In the latter case, my solution would be to create a specialized List class that returns a comma-separated string of the names of objects that it contains. Make the class smart enough that it constructs the name string on the fly as objects are added and removed from it. Then return an instance of this list and call the name generation method as needed. Although it may be almost as efficient (and simpler) to simply delay calculation of the names until the first time the method is called and store it then (lazy loading). If you add/remove an object, you need only remove the calculated value and have it get recalculated on the next call.

Is it possible in Java to access private fields via reflection

Yes it is possible.

You need to use the getDeclaredField method (instead of the getField method), with the name of your private field:

Field privateField = Test.class.getDeclaredField("str");

Additionally, you need to set this Field to be accessible, if you want to access a private field:

privateField.setAccessible(true);

Once that's done, you can use the get method on the Field instance, to access the value of the str field.

How to make google spreadsheet refresh itself every 1 minute?

If you're on the New Google Sheets, this is all you need to do, according to the docs:

change your recalculation setting to "On change and every minute" in your spreadsheet at File > Spreadsheet settings.

This will make the entire sheet update itself every minute, on the server side, regardless of whether you have the spreadsheet up in your browser or not.

If you're on the old Google Sheets, you'll want to add a cell with this formula to achieve the same functionality:

=GoogleClock()

EDIT to include old and new Google Sheets and change to =GoogleClock().

Node.js project naming conventions for files & folders

After some years with node, I can say that there are no conventions for the directory/file structure. However most (professional) express applications use a setup like:

/
  /bin - scripts, helpers, binaries
  /lib - your application
  /config - your configuration
  /public - your public files
  /test - your tests

An example which uses this setup is nodejs-starter.

I personally changed this setup to:

/
  /etc - contains configuration
  /app - front-end javascript files
    /config - loads config
    /models - loads models
  /bin - helper scripts
  /lib - back-end express files
    /config - loads config to app.settings
    /models - loads mongoose models
    /routes - sets up app.get('..')...
  /srv - contains public files
  /usr - contains templates
  /test - contains test files

In my opinion, the latter matches better with the Unix-style directory structure (whereas the former mixes this up a bit).

I also like this pattern to separate files:

lib/index.js

var http = require('http');
var express = require('express');

var app = express();

app.server = http.createServer(app);

require('./config')(app);

require('./models')(app);

require('./routes')(app);

app.server.listen(app.settings.port);

module.exports = app;

lib/static/index.js

var express = require('express');

module.exports = function(app) {

  app.use(express.static(app.settings.static.path));

};

This allows decoupling neatly all source code without having to bother dependencies. A really good solution for fighting nasty Javascript. A real-world example is nearby which uses this setup.

Update (filenames):

Regarding filenames most common are short, lowercase filenames. If your file can only be described with two words most JavaScript projects use an underscore as the delimiter.

Update (variables):

Regarding variables, the same "rules" apply as for filenames. Prototypes or classes, however, should use camelCase.

Update (styleguides):

How to open a file / browse dialog using javascript?

I worked it around through this "hiding" div ...

<div STYLE="position:absolute;display:none;"><INPUT type='file' id='file1' name='files[]'></div>

How do you disable viewport zooming on Mobile Safari?

This one should be working on iphone etc.

<meta name="viewport" content="width=device-width, initial-scale=1 initial-scale=1.0, maximum-scale=1.0, user-scalable=no">

How do I check whether a file exists without exceptions?

Although I always recommend using try and except statements, here are a few possibilities for you (my personal favourite is using os.access):

  1. Try opening the file:

    Opening the file will always verify the existence of the file. You can make a function just like so:

    def File_Existence(filepath):
        f = open(filepath)
        return True
    

    If it's False, it will stop execution with an unhanded IOError or OSError in later versions of Python. To catch the exception, you have to use a try except clause. Of course, you can always use a try except` statement like so (thanks to hsandt for making me think):

    def File_Existence(filepath):
        try:
            f = open(filepath)
        except IOError, OSError: # Note OSError is for later versions of Python
            return False
    
        return True
    
  2. Use os.path.exists(path):

    This will check the existence of what you specify. However, it checks for files and directories so beware about how you use it.

    import os.path
    >>> os.path.exists("this/is/a/directory")
    True
    >>> os.path.exists("this/is/a/file.txt")
    True
    >>> os.path.exists("not/a/directory")
    False
    
  3. Use os.access(path, mode):

    This will check whether you have access to the file. It will check for permissions. Based on the os.py documentation, typing in os.F_OK, it will check the existence of the path. However, using this will create a security hole, as someone can attack your file using the time between checking the permissions and opening the file. You should instead go directly to opening the file instead of checking its permissions. (EAFP vs LBYP). If you're not going to open the file afterwards, and only checking its existence, then you can use this.

    Anyway, here:

    >>> import os
    >>> os.access("/is/a/file.txt", os.F_OK)
    True
    

I should also mention that there are two ways that you will not be able to verify the existence of a file. Either the issue will be permission denied or no such file or directory. If you catch an IOError, set the IOError as e (like my first option), and then type in print(e.args) so that you can hopefully determine your issue. I hope it helps! :)

How do you underline a text in Android XML?

You can use the markup below, but note that if you set the textAllCaps to true the underline effect would be removed.

<resource>
    <string name="my_string_value">I am <u>underlined</u>.</string>
</resources>


Note

Using textAllCaps with a string (login_change_settings) that contains markup; the markup will be dropped by the caps conversion

The textAllCaps text transform will end up calling toString on the CharSequence, which has the net effect of removing any markup such as . This check looks for usages of strings containing markup that also specify textAllCaps=true.

How to fix Error: this class is not key value coding-compliant for the key tableView.'

Any chance that you changed the name of your table view from "tableView" to "myTableView" at some point?

Intellij reformat on file save

If it's about Prettier, just use a File Watcher :

references => Tools => File Watchers => click + to add a new watcher => Prettier

https://prettier.io/docs/en/webstorm.html#running-prettier-on-save-using-file-watcher

How to debug in Android Studio using adb over WiFi

Here are simple steps to implement Android App debugging using ADB over wifi:

Required: You need to connect android device and computer to the same router via wifi. You can use Android Wifi tethering also.

Step 1: Connect Android device via USB (with developer mode enabled), and check its connection via adb devices.

Step 2: Open cmd/terminal and the path of your ../sdk/platform-tools.

Step 3: Execute command adb devices.

Step 4: Execute command adb -d shell (for device) OR adb -e shell (for emulator). Here you will get the shell access to the device.

Step 5: Execute command ipconfig (Windows command) or ifconfig (Linux command) and check the ip-address of it.

Step 6: Not disconnect/remove device USB and execute command adb tcpip 5000, to open tcpip socket port 5000 for adb debugging. You can open it on any port which is not currently occupied.

Step 7: Now execute command adb connect <ip-address>:<port>. eg: adb connect 192.168.1.90:5000 (where ip-address is device's wifi address and port which you have opened).

Now, run adb device and check the debugging device is now connected wirelessly via wifi.

Happy Coding...!

C# : Passing a Generic Object

You're missing at least a couple of things:

  • Unless you're using reflection, the type arguments need to be known at compile-time, so you can't use

    PrintGeneric<test2.GetType()>
    

    ... although in this case you don't need to anyway

  • PrintGeneric doesn't know anything about T at the moment, so the compiler can't find a member called T

Options:

  • Put a property in the ITest interface, and change PrintGeneric to constrain T:

    public void PrintGeneric<T>(T test) where T : ITest
    {
        Console.WriteLine("Generic : " + test.PropertyFromInterface);
    }
    
  • Put a property in the ITest interface and remove the generics entirely:

    public void PrintGeneric(ITest test)
    {
        Console.WriteLine("Property : " + test.PropertyFromInterface);
    }
    
  • Use dynamic typing instead of generics if you're using C# 4

How to get selected path and name of the file opened with file dialog?

To extract only the filename from the path, you can do the following:

varFileName = Mid(fDialog.SelectedItems(1), InStrRev(fDialog.SelectedItems(1), "\") + 1, Len(fDialog.SelectedItems(1)))

How to get the index with the key in Python dictionary?

Use OrderedDicts: http://docs.python.org/2/library/collections.html#collections.OrderedDict

>>> x = OrderedDict((("a", "1"), ("c", '3'), ("b", "2")))
>>> x["d"] = 4
>>> x.keys().index("d")
3
>>> x.keys().index("c")
1

For those using Python 3

>>> list(x.keys()).index("c")
1

How do I find the value of $CATALINA_HOME?

Tomcat can tell you in several ways. Here's the easiest:

 $ /path/to/catalina.sh version
Using CATALINA_BASE:   /usr/local/apache-tomcat-7.0.29
Using CATALINA_HOME:   /usr/local/apache-tomcat-7.0.29
Using CATALINA_TMPDIR: /usr/local/apache-tomcat-7.0.29/temp
Using JRE_HOME:        /System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home
Using CLASSPATH:       /usr/local/apache-tomcat-7.0.29/bin/bootstrap.jar:/usr/local/apache-tomcat-7.0.29/bin/tomcat-juli.jar
Server version: Apache Tomcat/7.0.29
Server built:   Jul 3 2012 11:31:52
Server number:  7.0.29.0
OS Name:        Mac OS X
OS Version:     10.7.4
Architecture:   x86_64
JVM Version:    1.6.0_33-b03-424-11M3720
JVM Vendor:     Apple Inc.

If you don't know where catalina.sh is (or it never gets called), you can usually find it via ps:

$ ps aux | grep catalina
chris            930   0.0  3.1  2987336 258328 s000  S    Wed01PM   2:29.43 /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/java -Dnop -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.library.path=/usr/local/apache-tomcat-7.0.29/lib -Djava.endorsed.dirs=/usr/local/apache-tomcat-7.0.29/endorsed -classpath /usr/local/apache-tomcat-7.0.29/bin/bootstrap.jar:/usr/local/apache-tomcat-7.0.29/bin/tomcat-juli.jar -Dcatalina.base=/Users/chris/blah/blah -Dcatalina.home=/usr/local/apache-tomcat-7.0.29 -Djava.io.tmpdir=/Users/chris/blah/blah/temp org.apache.catalina.startup.Bootstrap start

From the ps output, you can see both catalina.home and catalina.base. catalina.home is where the Tomcat base files are installed, and catalina.base is where the running configuration of Tomcat exists. These are often set to the same value unless you have configured your Tomcat for multiple (configuration) instances to be launched from a single Tomcat base install.

You can also interrogate the JVM directly if you can't find it in a ps listing:

$ jinfo -sysprops 930 | grep catalina
Attaching to process ID 930, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 20.8-b03-424
catalina.base = /Users/chris/blah/blah
[...]
catalina.home = /usr/local/apache-tomcat-7.0.29

If you can't manage that, you can always try to write a JSP that dumps the values of the two system properties catalina.home and catalina.base.

What's the easy way to auto create non existing dir in ansible

AFAIK, the only way this could be done is by using the state=directory option. While template module supports most of copy options, which in turn supports most file options, you can not use something like state=directory with it. Moreover, it would be quite confusing (would it mean that {{project_root}}/conf/code.conf is a directory ? or would it mean that {{project_root}}/conf/ should be created first.

So I don't think this is possible right now without adding a previous file task.

- file: 
    path: "{{project_root}}/conf"
    state: directory
    recurse: yes

Chrome javascript debugger breakpoints don't do anything?

This may be a Chrome bug. Unfortunately Chrome routinely breaks debugging. It often has some kind of memory leak and it often breaks or changes every few releases.

Debugging with formatted sources is currently extremely unreliable.

It's possible you're also trying to break on dead code.

To be certain it's not the browser you should also try to debug it in firefox.

How to output (to a log) a multi-level array in a format that is human-readable?

http://php.net/manual/en/function.print-r.php This function can be used to format output,

$output = print_r($array,1);

$output is a string variable, it can be logged like every other string. In pure php you can use trigger_error

Ex. trigger_error($output);

http://php.net/manual/en/function.trigger-error.php

if you need to format it also in html, you can use <pre> tag

length and length() in Java

In Java, an Array stores its length separately from the structure that actually holds the data. When you create an Array, you specify its length, and that becomes a defining attribute of the Array. No matter what you do to an Array of length N (change values, null things out, etc.), it will always be an Array of length N.

A String's length is incidental; it is not an attribute of the String, but a byproduct. Though Java Strings are in fact immutable, if it were possible to change their contents, you could change their length. Knocking off the last character (if it were possible) would lower the length.

I understand this is a fine distinction, and I may get voted down for it, but it's true. If I make an Array of length 4, that length of four is a defining characteristic of the Array, and is true regardless of what is held within. If I make a String that contains "dogs", that String is length 4 because it happens to contain four characters.

I see this as justification for doing one with an attribute and the other with a method. In truth, it may just be an unintentional inconsistency, but it's always made sense to me, and this is always how I've thought about it.

Static methods - How to call a method from another method?

NOTE - it looks like the question has changed some. The answer to the question of how you call an instance method from a static method is that you can't without passing an instance in as an argument or instantiating that instance inside the static method.

What follows is mostly to answer "how do you call a static method from another static method":

Bear in mind that there is a difference between static methods and class methods in Python. A static method takes no implicit first argument, while a class method takes the class as the implicit first argument (usually cls by convention). With that in mind, here's how you would do that:

If it's a static method:

test.dosomethingelse()

If it's a class method:

cls.dosomethingelse()

Reading file using fscanf() in C

First of all, you're testing fp twice. so printf("Error Reading File\n"); never gets executed.

Then, the output of fscanf should be equal to 2 since you're reading two values.

Possible to extend types in Typescript?

May be below approach will be helpful for someone TS with reactjs

interface Event {
   name: string;
   dateCreated: string;
   type: string;
}

interface UserEvent<T> extends Event<T> {
    UserId: string;
}

String to HashMap JAVA

try

 String s = "SALES:0,SALE_PRODUCTS:1,EXPENSES:2,EXPENSES_ITEMS:3";
    HashMap<String,Integer> hm =new HashMap<String,Integer>();
    for(String s1:s.split(",")){
       String[] s2 = s1.split(":");
        hm.put(s2[0], Integer.parseInt(s2[1]));
    }

Removing all script tags from html with JS Regular Expression

Here are a variety of shell scripts you can use to strip out different elements.

# doctype
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/<\!DOCTYPE\s\+html[^>]*>/<\!DOCTYPE html>/gi" {} \;

# meta charset
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/<meta[^>]*content=[\"'][^\"']*utf-8[\"'][^>]*>/<meta charset=\"utf-8\">/gi" {} \;

# script text/javascript
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<script[^>]*\)\(\stype=[\"']text\/javascript[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

# style text/css
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<style[^>]*\)\(\stype=[\"']text\/css[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

# html xmlns
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<html[^>]*\)\(\sxmlns=[\"'][^\"']*[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

# html xml:lang
find . -regex ".*\.\(html\|py\)$" -type f -exec sed -i "s/\(<html[^>]*\)\(\sxml:lang=[\"'][^\"']*[\"']\)\(\s\?[^>]*>\)/\1\3/gi" {} \;

Does :before not work on img elements?

Try ::after on previous element.

How do I plot in real-time in a while loop using matplotlib?

show is probably not the best choice for this. What I would do is use pyplot.draw() instead. You also might want to include a small time delay (e.g., time.sleep(0.05)) in the loop so that you can see the plots happening. If I make these changes to your example it works for me and I see each point appearing one at a time.

Setting the classpath in java using Eclipse IDE

Try this:

Project -> Properties -> Java Build Path -> Add Class Folder.

If it doesnt work, please be specific in what way your compilation fails, specifically post the error messages Eclipse returns, and i will know what to do about it.

jquery clear input default value

$(document).ready(function() {
  //...
//clear on focus
$('.input').focus(function() {
    $('.input').val("");
});
   //clear when submitted
$('.button').click(function() {
    $('.input').val("");
});

});

How to get Java Decompiler / JD / JD-Eclipse running in Eclipse Helios

if you need to decompile standalone jar try JD-GUI by the same autor (of JD-Eclipse). It is a standalone application (does not need eclipse). It can open both *.class and *.jar files. Interesting enough it needs .Net installed (as do JD-Eclipse indeed), but otherwise works like a charm.

Find it here:

http://jd.benow.ca/

Regards,

Get latitude and longitude automatically using php, API

...and don't forget "$region" for the code to work:

$address = "Salzburg";
$address = str_replace(" ", "+", $address);
$region = "Austria";

$json = file_get_contents("http://maps.google.com/maps/api/geocode/json?address=$address&sensor=false&region=$region");
$json = json_decode($json);

$lat = $json->{'results'}[0]->{'geometry'}->{'location'}->{'lat'};
$long = $json->{'results'}[0]->{'geometry'}->{'location'}->{'lng'};
echo $lat."</br>".$long;

Initialize empty vector in structure - c++

Both std::string and std::vector<T> have constructors initializing the object to be empty. You could use std::vector<unsigned char>() but I'd remove the initializer.

Center align with table-cell

This would be easier to do with flexbox. Using flexbox will let you not to specify the height of your content and can adjust automatically on the height it contains.

DEMO

here's the gist of the demo

.container{

  display: flex;
  height: 100%;
  justify-content: center;
  align-items: center;

}

html

<div class="container">
  <div class='content'> //you can size this anyway you want
    put anything you want here,
  </div>
</div>

enter image description here

IF/ELSE Stored Procedure

try

IF(@Trans_type = 'subscr_signup')    
BEGIN 
 set @tmpType = 'premium' 
 END
ELSE iF(@Trans_type = 'subscr_cancel')  
  begin
     set    @tmpType = 'basic'  
  END

How do you check if a JavaScript Object is a DOM Object?

I have a special way to do this that has not yet been mentioned in the answers.

My solution is based on four tests. If the object passes all four, then it is an element:

  1. The object is not null.

  2. The object has a method called "appendChild".

  3. The method "appendChild" was inherited from the Node class, and isn't just an imposter method (a user-created property with an identical name).

  4. The object is of Node Type 1 (Element). Objects that inherit methods from the Node class are always Nodes, but not necessarily Elements.

Q: How do I check if a given property is inherited and isn't just an imposter?

A: A simple test to see if a method was truly inherited from Node is to first verify that the property has a type of "object" or "function". Next, convert the property to a string and check if the result contains the text "[Native Code]". If the result looks something like this:

function appendChild(){
[Native Code]
}

Then the method has been inherited from the Node object. See https://davidwalsh.name/detect-native-function

And finally, bringing all the tests together, the solution is:

function ObjectIsElement(obj) {
    var IsElem = true;
    if (obj == null) {
        IsElem = false;
    } else if (typeof(obj.appendChild) != "object" && typeof(obj.appendChild) != "function") {
        //IE8 and below returns "object" when getting the type of a function, IE9+ returns "function"
        IsElem = false;
    } else if ((obj.appendChild + '').replace(/[\r\n\t\b\f\v\xC2\xA0\x00-\x1F\x7F-\x9F ]/ig, '').search(/\{\[NativeCode]}$/i) == -1) {
        IsElem = false;
    } else if (obj.nodeType != 1) {
        IsElem = false;
    }
    return IsElem;
}

Can we create an instance of an interface in Java?

Normaly, you can create a reference for an interface. But you cant create an instance for interface.

How to change background color in the Notepad++ text editor?

If anyone wants to enable dark mode, you may follow the below steps

  • Open your Notepad++, and select “Settings” on the menu bar, and choose “Style configurator”.
  • Select theme “Obsidian” (you can choose other dark themes)
  • Click on Save&Colse

enter image description here

Sorting arrays in NumPy by column

@steve's answer is actually the most elegant way of doing it.

For the "correct" way see the order keyword argument of numpy.ndarray.sort

However, you'll need to view your array as an array with fields (a structured array).

The "correct" way is quite ugly if you didn't initially define your array with fields...

As a quick example, to sort it and return a copy:

In [1]: import numpy as np

In [2]: a = np.array([[1,2,3],[4,5,6],[0,0,1]])

In [3]: np.sort(a.view('i8,i8,i8'), order=['f1'], axis=0).view(np.int)
Out[3]: 
array([[0, 0, 1],
       [1, 2, 3],
       [4, 5, 6]])

To sort it in-place:

In [6]: a.view('i8,i8,i8').sort(order=['f1'], axis=0) #<-- returns None

In [7]: a
Out[7]: 
array([[0, 0, 1],
       [1, 2, 3],
       [4, 5, 6]])

@Steve's really is the most elegant way to do it, as far as I know...

The only advantage to this method is that the "order" argument is a list of the fields to order the search by. For example, you can sort by the second column, then the third column, then the first column by supplying order=['f1','f2','f0'].

adb shell command to make Android package uninstall dialog appear

You can do it from adb using this command:

adb shell am start -a android.intent.action.DELETE -d package:<your app package>

Can anyone explain IEnumerable and IEnumerator to me?

IEnumerable is a box that contains Ienumerator. IEnumerable is base interface for all the collections. foreach loop can operate if the collection implements IEnumerable. In the below code it explains the step of having our own Enumerator. Lets first define our Class of which we are going to make the collection.

public class Customer
{
    public String Name { get; set; }
    public String City { get; set; }
    public long Mobile { get; set; }
    public double Amount { get; set; }
}

Now we will define the Class which will act as a collection for our class Customer. Notice that it is implementing the interface IEnumerable. So that we have to implement the method GetEnumerator. This will return our custom Enumerator.

public class CustomerList : IEnumerable
{
    Customer[] customers = new Customer[4];
    public CustomerList()
    {
        customers[0] = new Customer { Name = "Bijay Thapa", City = "LA", Mobile = 9841639665, Amount = 89.45 };
        customers[1] = new Customer { Name = "Jack", City = "NYC", Mobile = 9175869002, Amount = 426.00 };
        customers[2] = new Customer { Name = "Anil min", City = "Kathmandu", Mobile = 9173694005, Amount = 5896.20 };
        customers[3] = new Customer { Name = "Jim sin", City = "Delhi", Mobile = 64214556002, Amount = 596.20 };
    }

    public int Count()
    {
        return customers.Count();
    }
    public Customer this[int index]
    {
        get
        {
            return customers[index];
        }
    }
    public IEnumerator GetEnumerator()
    {
        return customers.GetEnumerator(); // we can do this but we are going to make our own Enumerator
        return new CustomerEnumerator(this);
    }
}

Now we are going to create our own custom Enumerator as follow. So, we have to implement method MoveNext.

 public class CustomerEnumerator : IEnumerator
    {
        CustomerList coll;
        Customer CurrentCustomer;
        int currentIndex;
        public CustomerEnumerator(CustomerList customerList)
        {
            coll = customerList;
            currentIndex = -1;
        }

        public object Current => CurrentCustomer;

        public bool MoveNext()
        {
            if ((currentIndex++) >= coll.Count() - 1)
                return false;
            else
                CurrentCustomer = coll[currentIndex];
            return true;
        }

        public void Reset()
        {
            // we dont have to implement this method.
        }
    }

Now we can use foreach loop over our collection like below;

    class EnumeratorExample
    {
        static void Main(String[] args)
        {

            CustomerList custList = new CustomerList();
            foreach (Customer cust in custList)
            {
                Console.WriteLine("Customer Name:"+cust.Name + " City Name:" + cust.City + " Mobile Number:" + cust.Amount);
            }
            Console.Read();

        }
    }

Bash Script : what does #!/bin/bash mean?

When the first characters in a script are #!, that is called the shebang. If your file starts with #!/path/to/something the standard is to run something and pass the rest of the file to that program as an input.

With that said, the difference between #!/bin/bash, #!/bin/sh, or even #!/bin/zsh is whether the bash, sh, or zsh programs are used to interpret the rest of the file. bash and sh are just different programs, traditionally. On some Linux systems they are two copies of the same program. On other Linux systems, sh is a link to dash, and on traditional Unix systems (Solaris, Irix, etc) bash is usually a completely different program from sh.

Of course, the rest of the line doesn't have to end in sh. It could just as well be #!/usr/bin/python, #!/usr/bin/perl, or even #!/usr/local/bin/my_own_scripting_language.

Should I Dispose() DataSet and DataTable?

Do you create the DataTables yourself? Because iterating through the children of any Object (as in DataSet.Tables) is usually not needed, as it's the job of the Parent to dispose all its child members.

Generally, the rule is: If you created it and it implements IDisposable, Dispose it. If you did NOT create it, then do NOT dispose it, that's the job of the parent object. But each object may have special rules, check the Documentation.

For .NET 3.5, it explicitly says "Dispose it when not using anymore", so that's what I would do.

Convert line endings

Doing this with POSIX is tricky:

  • POSIX Sed does not support \r or \15. Even if it did, the in place option -i is not POSIX

  • POSIX Awk does support \r and \15, however the -i inplace option is not POSIX

  • d2u and dos2unix are not POSIX utilities, but ex is

  • POSIX ex does not support \r, \15, \n or \12

To remove carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\r","");print>ARGV[1]}' file

To add carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\n","\r&");print>ARGV[1]}' file

SQL Server Escape an Underscore

These solutions totally make sense. Unfortunately, neither worked for me as expected. Instead of trying to hassle with it, I went with a work around:

select * from information_schema.columns 
where replace(table_name,'_','!') not like '%!%'
order by table_name

Set order of columns in pandas dataframe

You could also do something like df = df[['x', 'y', 'a', 'b']]

import pandas as pd
frame = pd.DataFrame({'one thing':[1,2,3,4],'second thing':[0.1,0.2,1,2],'other thing':['a','e','i','o']})
frame = frame[['second thing', 'other thing', 'one thing']]
print frame
   second thing other thing  one thing
0           0.1           a          1
1           0.2           e          2
2           1.0           i          3
3           2.0           o          4

Also, you can get the list of columns with:

cols = list(df.columns.values)

The output will produce something like this:

['x', 'y', 'a', 'b']

Which is then easy to rearrange manually.