Programs & Examples On #Import hooks

How do I make a dotted/dashed line in Android?

The only thing that worked for me and I think it is the simplest way is using a Path with a paint object like this:

    Paint paintDash = new Paint();
    paintDash.setARGB(255, 0, 0, 0);
    paintDash.setStyle(Paint.Style.STROKE);
    paintDash.setPathEffect(new DashPathEffect(new float[]{10f,10f}, 0));
    paintDash.setStrokeWidth(2);
    Path pathDashLine = new Path();

Then onDraw(): (important call reset if you change those points between ondraw calls, cause Path save all the movements)

    pathDashLine.reset();
    pathDashLine.moveTo(porigenX, porigenY);
    pathDashLine.lineTo(cursorX,cursorY);
    c.drawPath(pathDashLine, paintDash);

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

My solution would be to use a parameterised query, as the connectivity objects take care of formatting the data correctly (including ensuring the correct data-type, and escaping "dangerous" characters where applicable):

// Assuming "conn" is an open SqlConnection
using(SqlCommand cmd = new SqlCommand("INSERT INTO mssqltable(varbinarycolumn) VALUES (@binaryValue)", conn))
{
    // Replace 8000, below, with the correct size of the field
    cmd.Parameters.Add("@binaryValue", SqlDbType.VarBinary, 8000).Value = arraytoinsert;
    cmd.ExecuteNonQuery();
}

Edit: Added the wrapping "using" statement as suggested by John Saunders to correctly dispose of the SqlCommand after it is finished with

Maven skip tests

During maven compilation you can skip test execution by adding following plugin in pom.xml

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.20.1</version>
    <configuration>
         <skipTests>true</skipTests>
    </configuration>
</plugin>

MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near

MYSQL PROCEDURE steps:

  1. change delimiter from default ' ; ' to ' // '

DELIMITER //

  1. create PROCEDURE, you can refer syntax

    NOTE: Don't forget to end statement with ' ; '

create procedure ProG() 
begin 
SELECT * FROM hs_hr_employee_leave_quota;
end;//
  1. Change delimiter back to ' ; '

delimiter ;

  1. Now to execute:

call ProG();

How to send only one UDP packet with netcat?

If you are using bash, you might as well write

echo -n "hello" >/dev/udp/localhost/8000

and avoid all the idiosyncrasies and incompatibilities of netcat.

This also works sending to other hosts, ex:

echo -n "hello" >/dev/udp/remotehost/8000

These are not "real" devices on the file system, but bash "special" aliases. There is additional information in the Bash Manual.

comma separated string of selected values in mysql

Check this

SELECT GROUP_CONCAT(id)  FROM table_level where parent_id=4 group by parent_id;

Best way to randomize an array with .NET

private ArrayList ShuffleArrayList(ArrayList source)
{
    ArrayList sortedList = new ArrayList();
    Random generator = new Random();

    while (source.Count > 0)
    {
        int position = generator.Next(source.Count);
        sortedList.Add(source[position]);
        source.RemoveAt(position);
    }  
    return sortedList;
}

How to split a dataframe string column into two columns?

TL;DR version:

For the simple case of:

  • I have a text column with a delimiter and I want two columns

The simplest solution is:

df[['A', 'B']] = df['AB'].str.split(' ', 1, expand=True)

You must use expand=True if your strings have a non-uniform number of splits and you want None to replace the missing values.

Notice how, in either case, the .tolist() method is not necessary. Neither is zip().

In detail:

Andy Hayden's solution is most excellent in demonstrating the power of the str.extract() method.

But for a simple split over a known separator (like, splitting by dashes, or splitting by whitespace), the .str.split() method is enough1. It operates on a column (Series) of strings, and returns a column (Series) of lists:

>>> import pandas as pd
>>> df = pd.DataFrame({'AB': ['A1-B1', 'A2-B2']})
>>> df

      AB
0  A1-B1
1  A2-B2
>>> df['AB_split'] = df['AB'].str.split('-')
>>> df

      AB  AB_split
0  A1-B1  [A1, B1]
1  A2-B2  [A2, B2]

1: If you're unsure what the first two parameters of .str.split() do, I recommend the docs for the plain Python version of the method.

But how do you go from:

  • a column containing two-element lists

to:

  • two columns, each containing the respective element of the lists?

Well, we need to take a closer look at the .str attribute of a column.

It's a magical object that is used to collect methods that treat each element in a column as a string, and then apply the respective method in each element as efficient as possible:

>>> upper_lower_df = pd.DataFrame({"U": ["A", "B", "C"]})
>>> upper_lower_df

   U
0  A
1  B
2  C
>>> upper_lower_df["L"] = upper_lower_df["U"].str.lower()
>>> upper_lower_df

   U  L
0  A  a
1  B  b
2  C  c

But it also has an "indexing" interface for getting each element of a string by its index:

>>> df['AB'].str[0]

0    A
1    A
Name: AB, dtype: object

>>> df['AB'].str[1]

0    1
1    2
Name: AB, dtype: object

Of course, this indexing interface of .str doesn't really care if each element it's indexing is actually a string, as long as it can be indexed, so:

>>> df['AB'].str.split('-', 1).str[0]

0    A1
1    A2
Name: AB, dtype: object

>>> df['AB'].str.split('-', 1).str[1]

0    B1
1    B2
Name: AB, dtype: object

Then, it's a simple matter of taking advantage of the Python tuple unpacking of iterables to do

>>> df['A'], df['B'] = df['AB'].str.split('-', 1).str
>>> df

      AB  AB_split   A   B
0  A1-B1  [A1, B1]  A1  B1
1  A2-B2  [A2, B2]  A2  B2

Of course, getting a DataFrame out of splitting a column of strings is so useful that the .str.split() method can do it for you with the expand=True parameter:

>>> df['AB'].str.split('-', 1, expand=True)

    0   1
0  A1  B1
1  A2  B2

So, another way of accomplishing what we wanted is to do:

>>> df = df[['AB']]
>>> df

      AB
0  A1-B1
1  A2-B2

>>> df.join(df['AB'].str.split('-', 1, expand=True).rename(columns={0:'A', 1:'B'}))

      AB   A   B
0  A1-B1  A1  B1
1  A2-B2  A2  B2

The expand=True version, although longer, has a distinct advantage over the tuple unpacking method. Tuple unpacking doesn't deal well with splits of different lengths:

>>> df = pd.DataFrame({'AB': ['A1-B1', 'A2-B2', 'A3-B3-C3']})
>>> df
         AB
0     A1-B1
1     A2-B2
2  A3-B3-C3
>>> df['A'], df['B'], df['C'] = df['AB'].str.split('-')
Traceback (most recent call last):
  [...]    
ValueError: Length of values does not match length of index
>>> 

But expand=True handles it nicely by placing None in the columns for which there aren't enough "splits":

>>> df.join(
...     df['AB'].str.split('-', expand=True).rename(
...         columns={0:'A', 1:'B', 2:'C'}
...     )
... )
         AB   A   B     C
0     A1-B1  A1  B1  None
1     A2-B2  A2  B2  None
2  A3-B3-C3  A3  B3    C3

How to get the filename without the extension from a path in Python?

import os
list = []
def getFileName( path ):
for file in os.listdir(path):
    #print file
    try:
        base=os.path.basename(file)
        splitbase=os.path.splitext(base)
        ext = os.path.splitext(base)[1]
        if(ext):
            list.append(base)
        else:
            newpath = path+"/"+file
            #print path
            getFileName(newpath)
    except:
        pass
return list

getFileName("/home/weexcel-java3/Desktop/backup")
print list

Where can I download IntelliJ IDEA Color Schemes?

Please note there are two very nice color schemes by default in IDEA 10.

The one that is included is named Railcasts. It is included with the Ruby plugin (free official plugin, install via plugin manager).

Railcasts IDEA 10 color scheme

Node.js + Nginx - What now?

You can also setup multiple domain with nginx, forwarding to multiple node.js processes.

For example to achieve these:

These ports (4000 and 5000) should be used to listen the app requests in your app code.

/etc/nginx/sites-enabled/domain1

server {
    listen 80;
    listen [::]:80;
    server_name domain1.com;
    access_log /var/log/nginx/domain1.access.log;
    location / {
        proxy_pass    http://127.0.0.1:4000/;
    }
}

In /etc/nginx/sites-enabled/domain2

server {
    listen 80;
    listen [::]:80;
    server_name domain2.com;
    access_log /var/log/nginx/domain2.access.log;
    location / {
        proxy_pass    http://127.0.0.1:5000/;
    }
}

Save the console.log in Chrome to a file

There is an open-source javascript plugin that does just that, but for any browser - debugout.js

Debugout.js records and save console.logs so your application can access them. Full disclosure, I wrote it. It formats different types appropriately, can handle nested objects and arrays, and can optionally put a timestamp next to each log. You can also toggle live-logging in one place, and without having to remove all your logging statements.

Detect changes in the DOM

MutationObserver = window.MutationObserver || window.WebKitMutationObserver;

var observer = new MutationObserver(function(mutations, observer) {
    // fired when a mutation occurs
    console.log(mutations, observer);
    // ...
});

// define what element should be observed by the observer
// and what types of mutations trigger the callback
observer.observe(document, {
  subtree: true,
  attributes: true
  //...
});

Complete explanations: https://stackoverflow.com/a/11546242/6569224

How can I use if/else in a dictionary comprehension?

You've already got it: A if test else B is a valid Python expression. The only problem with your dict comprehension as shown is that the place for an expression in a dict comprehension must have two expressions, separated by a colon:

{ (some_key if condition else default_key):(something_if_true if condition
          else something_if_false) for key, value in dict_.items() }

The final if clause acts as a filter, which is different from having the conditional expression.


Worth mentioning that you don't need to have an if-else condition for both the key and the value. For example, {(a if condition else b): value for key, value in dict.items()} will work.

How to determine if a string is a number with C++?

Why reinvent the wheel? The C standard library (available in C++ as well) has a function that does exactly this:

char* p;
long converted = strtol(s, &p, 10);
if (*p) {
    // conversion failed because the input wasn't a number
}
else {
    // use converted
}

If you want to handle fractions or scientific notation, go with strtod instead (you'll get a double result).

If you want to allow hexadecimal and octal constants in C/C++ style ("0xABC"), then make the last parameter 0 instead.

Your function then can be written as

bool isParam(string line)
{
    char* p;
    strtol(line.c_str(), &p, 10);
    return *p == 0;
}

Getting error: ISO C++ forbids declaration of with no type

Your declaration is int ttTreeInsert(int value);

However, your definition/implementation is

ttTree::ttTreeInsert(int value)
{
}

Notice that the return type int is missing in the implementation. Instead it should be

int ttTree::ttTreeInsert(int value)
{
    return 1; // or some valid int
}

Find a private field with Reflection?

Here is some extension methods for simple get and set private fields and properties (properties with setter):

usage example:

    public class Foo
    {
        private int Bar = 5;
    }

    var targetObject = new Foo();
    var barValue = targetObject.GetMemberValue("Bar");//Result is 5
    targetObject.SetMemberValue("Bar", 10);//Sets Bar to 10

Code:

    /// <summary>
    /// Extensions methos for using reflection to get / set member values
    /// </summary>
    public static class ReflectionExtensions
    {
        /// <summary>
        /// Gets the public or private member using reflection.
        /// </summary>
        /// <param name="obj">The source target.</param>
        /// <param name="memberName">Name of the field or property.</param>
        /// <returns>the value of member</returns>
        public static object GetMemberValue(this object obj, string memberName)
        {
            var memInf = GetMemberInfo(obj, memberName);

            if (memInf == null)
                throw new System.Exception("memberName");

            if (memInf is System.Reflection.PropertyInfo)
                return memInf.As<System.Reflection.PropertyInfo>().GetValue(obj, null);

            if (memInf is System.Reflection.FieldInfo)
                return memInf.As<System.Reflection.FieldInfo>().GetValue(obj);

            throw new System.Exception();
        }

        /// <summary>
        /// Gets the public or private member using reflection.
        /// </summary>
        /// <param name="obj">The target object.</param>
        /// <param name="memberName">Name of the field or property.</param>
        /// <returns>Old Value</returns>
        public static object SetMemberValue(this object obj, string memberName, object newValue)
        {
            var memInf = GetMemberInfo(obj, memberName);


            if (memInf == null)
                throw new System.Exception("memberName");

            var oldValue = obj.GetMemberValue(memberName);

            if (memInf is System.Reflection.PropertyInfo)
                memInf.As<System.Reflection.PropertyInfo>().SetValue(obj, newValue, null);
            else if (memInf is System.Reflection.FieldInfo)
                memInf.As<System.Reflection.FieldInfo>().SetValue(obj, newValue);
            else
                throw new System.Exception();

            return oldValue;
        }

        /// <summary>
        /// Gets the member info
        /// </summary>
        /// <param name="obj">source object</param>
        /// <param name="memberName">name of member</param>
        /// <returns>instanse of MemberInfo corresponsing to member</returns>
        private static System.Reflection.MemberInfo GetMemberInfo(object obj, string memberName)
        {
            var prps = new System.Collections.Generic.List<System.Reflection.PropertyInfo>();

            prps.Add(obj.GetType().GetProperty(memberName,
                                               System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance |
                                               System.Reflection.BindingFlags.FlattenHierarchy));
            prps = System.Linq.Enumerable.ToList(System.Linq.Enumerable.Where( prps,i => !ReferenceEquals(i, null)));
            if (prps.Count != 0)
                return prps[0];

            var flds = new System.Collections.Generic.List<System.Reflection.FieldInfo>();

            flds.Add(obj.GetType().GetField(memberName,
                                            System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance |
                                            System.Reflection.BindingFlags.FlattenHierarchy));

            //to add more types of properties

            flds = System.Linq.Enumerable.ToList(System.Linq.Enumerable.Where(flds, i => !ReferenceEquals(i, null)));

            if (flds.Count != 0)
                return flds[0];

            return null;
        }

        [System.Diagnostics.DebuggerHidden]
        private static T As<T>(this object obj)
        {
            return (T)obj;
        }
    }

How to compare character ignoring case in primitive types

Generic methods to compare a char at a position between 2 strings with ignore case.

public static boolean isEqualIngoreCase(char one, char two){
    return Character.toLowerCase(one)==Character .toLowerCase(two);
}

public static boolean isEqualStringCharIgnoreCase(String one, String two, int position){
    char oneChar = one.charAt(position);
    char twoChar = two.charAt(position);
    return isEqualIngoreCase(oneChar, twoChar);
}

Function call

boolean isFirstCharEqual = isEqualStringCharIgnoreCase("abc", "ABC", 0)

Is a DIV inside a TD a bad idea?

It breaks semantics, that's all. It works fine, but there may be screen readers or something down the road that won't enjoy processing your HTML if you "break semantics".

How to remove all click event handlers using jQuery?

If you used...

$(function(){
    function myFunc() {
        // ... do something ...
    };
    $('#saveBtn').click(myFunc);
});

... then it will be easier to unbind later.

How do I test which class an object is in Objective-C?

If you want to check for a specific class then you can use

if([MyClass class] == [myClassObj class]) {
//your object is instance of MyClass
}

How to assign the output of a command to a Makefile variable

With GNU Make, you can use shell and eval to store, run, and assign output from arbitrary command line invocations. The difference between the example below and those which use := is the := assignment happens once (when it is encountered) and for all. Recursively expanded variables set with = are a bit more "lazy"; references to other variables remain until the variable itself is referenced, and the subsequent recursive expansion takes place each time the variable is referenced, which is desirable for making "consistent, callable, snippets". See the manual on setting variables for more info.

# Generate a random number.
# This is not run initially.
GENERATE_ID = $(shell od -vAn -N2 -tu2 < /dev/urandom)

# Generate a random number, and assign it to MY_ID
# This is not run initially.
SET_ID = $(eval MY_ID=$(GENERATE_ID))

# You can use .PHONY to tell make that we aren't building a target output file
.PHONY: mytarget
mytarget:
# This is empty when we begin
    @echo $(MY_ID)
# This recursively expands SET_ID, which calls the shell command and sets MY_ID
    $(SET_ID)
# This will now be a random number
    @echo $(MY_ID)
# Recursively expand SET_ID again, which calls the shell command (again) and sets MY_ID (again)
    $(SET_ID)
# This will now be a different random number
    @echo $(MY_ID)

How do you set up use HttpOnly cookies in PHP

Explanation here from Ilia... 5.2 only though

httpOnly cookie flag support in PHP 5.2

As stated in that article, you can set the header yourself in previous versions of PHP

header("Set-Cookie: hidden=value; httpOnly");

Regex to check whether a string contains only numbers

This is extreme overkill for your purpose, but here's what I use:

var numberReSnippet = "(?:NaN|-?(?:(?:\\d+|\\d*\\.\\d+)(?:[E|e][+|-]?\\d+)?|Infinity))";
var matchOnlyNumberRe = new RegExp("^("+ numberReSnippet + ")$");

To my knowledge, this matches all the variations on numbers that Java and JavaScript will ever throw at you, including "-Infinity", "1e-24" and "NaN". It also matches numbers you might type, such as "-.5".

As written, reSnippet is designed to be dropped into other regular expressions, so you can extract (or avoid) numbers. Despite all the parentheses, it contains no capturing groups. Thus "matchOnlyNumberRe" matches only strings that are numbers, and has a capturing group for the entire string.

Here are the Jasmine tests, so you can see what it does and doesn't handle:

describe("Number Regex", function() {
    var re = new RegExp("^("+ numberReSnippet + ")$");
    it("Matches Java and JavaScript numbers", function() {
        expect(re.test(         "1")).toBe(true);
        expect(re.test(       "0.2")).toBe(true);
        expect(re.test(     "0.4E4")).toBe(true);  // Java-style
        expect(re.test(       "-55")).toBe(true);
        expect(re.test(      "-0.6")).toBe(true);
        expect(re.test(  "-0.77E77")).toBe(true);
        expect(re.test(      "88E8")).toBe(true);
        expect(re.test(       "NaN")).toBe(true);
        expect(re.test(  "Infinity")).toBe(true);
        expect(re.test( "-Infinity")).toBe(true);
        expect(re.test(     "1e+24")).toBe(true);  // JavaScript-style
    });
    it("Matches fractions with a leading decimal point", function() {
        expect(re.test(        ".3")).toBe(true);
        expect(re.test(       "-.3")).toBe(true);
        expect(re.test(     ".3e-4")).toBe(true);
    });
    it("Doesn't match non-numbers", function() {
        expect(re.test(         ".")).toBe(false);
        expect(re.test(        "9.")).toBe(false);
        expect(re.test(          "")).toBe(false);
        expect(re.test(         "E")).toBe(false);
        expect(re.test(       "e24")).toBe(false);
        expect(re.test(   "1e+24.5")).toBe(false);
        expect(re.test("-.Infinity")).toBe(false);
    });
});

How to exit a 'git status' list in a terminal?

for windows :

Ctrl + q and c for exit the running situation .

How do I run a command on an already existing Docker container?

Assuming the image is using the default entrypoint /bin/sh -c, running /bin/bash will exit immediately in daemon mode (-d). If you want this container to run an interactive shell, use -it instead of -d. If you want to execute arbitrary commands in a container usually executing another process, you might want to try nsenter or nsinit. Have a look at https://blog.codecentric.de/en/2014/07/enter-docker-container/ for the details.

Compare two MySQL databases

I'm working with Nob Hill's Marketing team, I wanted to tell you I'll be happy to hear your questions, suggestion or anything else, please feel free to contact me.

We originally decided to create our tool from scratch because while there are other such products on the market, none of them do the job right. It’s quite easy to show you the differences between databases. It’s quite another to actually make one database like the other. Smooth migration, both of schema and data, has always been a challenge. Well, we have achieved it here.
We are so confident that it could provide you a smooth migration, than if it doesn’t – if the migration scripts it generates are not readable enough or won’t work for you, and we can’t fix it in five business days – you will get your own free copy!

http://www.nobhillsoft.com/NHDBCompare.aspx

In Bash, how do I add a string after each line in a file?

I prefer using awk. If there is only one column, use $0, else replace it with the last column.

One way,

awk '{print $0, "string to append after each line"}' file > new_file

or this,

awk '$0=$0"string to append after each line"' file > new_file

Converting BitmapImage to Bitmap and vice versa

This converts from System.Drawing.Bitmap to BitmapImage:

MemoryStream ms = new MemoryStream();
YOURBITMAP.Save(ms, System.Drawing.Imaging.ImageFormat.Bmp);
BitmapImage image = new BitmapImage();
image.BeginInit();
ms.Seek(0, SeekOrigin.Begin);
image.StreamSource = ms;
image.EndInit();

PHP save image file

No need to create a GD resource, as someone else suggested.

$input = 'http://images.websnapr.com/?size=size&key=Y64Q44QLt12u&url=http://google.com';
$output = 'google.com.jpg';
file_put_contents($output, file_get_contents($input));

Note: this solution only works if you're setup to allow fopen access to URLs. If the solution above doesn't work, you'll have to use cURL.

How to select rows with no matching entry in another table?

Here's a simple query:

SELECT t1.ID
FROM Table1 t1
    LEFT JOIN Table2 t2 ON t1.ID = t2.ID
WHERE t2.ID IS NULL

The key points are:

  1. LEFT JOIN is used; this will return ALL rows from Table1, regardless of whether or not there is a matching row in Table2.

  2. The WHERE t2.ID IS NULL clause; this will restrict the results returned to only those rows where the ID returned from Table2 is null - in other words there is NO record in Table2 for that particular ID from Table1. Table2.ID will be returned as NULL for all records from Table1 where the ID is not matched in Table2.

Convert varchar2 to Date ('MM/DD/YYYY') in PL/SQL

Easiest way is probably to convert from a VARCHAR to a DATE; then format it back to a VARCHAR again in the format you want;

SELECT TO_CHAR(TO_DATE(DOJ,'MM/DD/YYYY'), 'MM/DD/YYYY') FROM EmpTable;

An SQLfiddle to test with.

How to un-commit last un-pushed git commit without losing the changes

There are a lot of ways to do so, for example:

in case you have not pushed the commit publicly yet:

git reset HEAD~1 --soft   

That's it, your commit changes will be in your working directory, whereas the LAST commit will be removed from your current branch. See git reset man


In case you did push publicly (on a branch called 'master'):

git checkout -b MyCommit //save your commit in a separate branch just in case (so you don't have to dig it from reflog in case you screw up :) )

revert commit normally and push

git checkout master
git revert a8172f36 #hash of the commit you want to destroy
# this introduces a new commit (say, it's hash is 86b48ba) which removes changes, introduced in the commit in question (but those changes are still visible in the history)
git push origin master

now if you want to have those changes as you local changes in your working copy ("so that your local copy keeps the changes made in that commit") - just revert the revert commit with --no-commit option:

git revert --no-commit 86b48ba (hash of the revert commit).

I've crafted a small example: https://github.com/Isantipov/git-revert/commits/master

Image resizing client-side with JavaScript before upload to the server

Here's a gist which does this: https://gist.github.com/dcollien/312bce1270a5f511bf4a

(an es6 version, and a .js version which can be included in a script tag)

You can use it as follows:

<input type="file" id="select">
<img id="preview">
<script>
document.getElementById('select').onchange = function(evt) {
    ImageTools.resize(this.files[0], {
        width: 320, // maximum width
        height: 240 // maximum height
    }, function(blob, didItResize) {
        // didItResize will be true if it managed to resize it, otherwise false (and will return the original file as 'blob')
        document.getElementById('preview').src = window.URL.createObjectURL(blob);
        // you can also now upload this blob using an XHR.
    });
};
</script>

It includes a bunch of support detection and polyfills to make sure it works on as many browsers as I could manage.

(it also ignores gif images - in case they're animated)

Can we convert a byte array into an InputStream in Java?

If you use Robert Harder's Base64 utility, then you can do:

InputStream is = new Base64.InputStream(cph);

Or with sun's JRE, you can do:

InputStream is = new
com.sun.xml.internal.messaging.saaj.packaging.mime.util.BASE64DecoderStream(cph)

However don't rely on that class continuing to be a part of the JRE, or even continuing to do what it seems to do today. Sun say not to use it.

There are other Stack Overflow questions about Base64 decoding, such as this one.

fatal: Not a valid object name: 'master'

copying Superfly Jon's comment into an answer:

To create a new branch without committing on master, you can use:

git checkout -b <branchname>

How To Show And Hide Input Fields Based On Radio Button Selection

Replace all instances of visibility style to display

display:none //to hide
display:block //to show

Here's updated jsfiddle: http://jsfiddle.net/QAaHP/16/

You can do it using Mootools or jQuery functions to slide up/down but if you don't need animation effect it's probably too much for what you need.

CSS display is a faster and simpler approach.

How to make a div with a circular shape?

You can do following

FIDDLE

<div id="circle"></div>

CSS

#circle {
    width: 100px;
    height: 100px;
    background: red;
    -moz-border-radius: 50px;
    -webkit-border-radius: 50px;
    border-radius: 50px;
}

Other shape SOURCE

dpi value of default "large", "medium" and "small" text views android

To put it in another way, can we replicate the appearance of these text views without using the android:textAppearance attribute?

Like biegleux already said:

  • small represents 14sp
  • medium represents 18sp
  • large represents 22sp

If you want to use the small, medium or large value on any text in your Android app, you can just create a dimens.xml file in your values folder and define the text size there with the following 3 lines:

<dimen name="text_size_small">14sp</dimen>
<dimen name="text_size_medium">18sp</dimen>
<dimen name="text_size_large">22sp</dimen>

Here is an example for a TextView with large text from the dimens.xml file:

<TextView
  android:id="@+id/hello_world"
  android:text="hello world"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:textSize="@dimen/text_size_large"/>

.Net picking wrong referenced assembly version

This isn't a clear answer as to why, but we had this problem, here's our circumstances and what solved it:

Dev 1:

Solution contains Project A referencing a NuGet Package, and an MVC project referencing Project A. Enabled NuGet Package Restore, then updated the NuGet package. Got a runtime error complaining the NuGet lib can't be found - but the error is it looking for the older, non-updated version. Solution (and this is ridiculous): Set a breakpoint on the first line of code in the MVC project that calls Project A. Step in with F11. Solved - never had a problem again.

Dev 2:

Same solution and projects, but the magic set breakpoint and step in solution doesn't work. Looked everywhere for version redirects or other bad references to this Nuget package, removed package and reinstalled it, wiped bin, obj, Asp.Net Temp, nothing solved it. Finally, renamed Project A, ran the MVC project - fixed. Renamed it back to its original name, it stayed fixed.

I don't have any explanation for why that worked, but it did get us out of a serious lurch.

Global environment variables in a shell script

#!/bin/bash
export FOO=bar

or

#!/bin/bash
FOO=bar
export FOO

man export:

The shell shall give the export attribute to the variables corresponding to the specified names, which shall cause them to be in the environment of subsequently executed commands. If the name of a variable is followed by = word, then the value of that variable shall be set to word.

XML Carriage return encoding

To insert a CR into XML, you need to use its character entity &#13;.

This is because compliant XML parsers must, before parsing, translate CRLF and any CR not followed by a LF to a single LF. This behavior is defined in the End-of-Line handling section of the XML 1.0 specification.

Under what circumstances can I call findViewById with an Options Menu / Action Bar item?

I am trying to obtain a handle on one of the views in the Action Bar

I will assume that you mean something established via android:actionLayout in your <item> element of your <menu> resource.

I have tried calling findViewById(R.id.menu_item)

To retrieve the View associated with your android:actionLayout, call findItem() on the Menu to retrieve the MenuItem, then call getActionView() on the MenuItem. This can be done any time after you have inflated the menu resource.

The maximum value for an int type in Go

https://golang.org/ref/spec#Numeric_types for physical type limits.

The max values are defined in the math package so in your case: math.MaxUint32

Watch out as there is no overflow - incrementing past max causes wraparound.

Undefined index error PHP

TRY

<?php

  $rowID=$productid=$name=$price=$description="";  

   if (isset($_POST['submit'])) {
      $rowID = $_POST['rowID'];
      $productid = $_POST['productid']; //this is line 32 and so on...
      $name = $_POST['name'];
      $price = $_POST['price'];
      $description = $_POST['description'];

}

What is the parameter "next" used for in Express?

Next is used to pass control to the next middleware function. If not the request will be left hanging or open.

What is this date format? 2011-08-12T20:17:46.384Z

There are other ways to parse it rather than the first answer. To parse it:

(1) If you want to grab information about date and time, you can parse it to a ZonedDatetime(since Java 8) or Date(old) object:

// ZonedDateTime's default format requires a zone ID(like [Australia/Sydney]) in the end.
// Here, we provide a format which can parse the string correctly.
DateTimeFormatter dtf = DateTimeFormatter.ISO_DATE_TIME;
ZonedDateTime zdt = ZonedDateTime.parse("2011-08-12T20:17:46.384Z", dtf);

or

// 'T' is a literal.
// 'X' is ISO Zone Offset[like +01, -08]; For UTC, it is interpreted as 'Z'(Zero) literal.
String pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSX";

// since no built-in format, we provides pattern directly.
DateFormat df = new SimpleDateFormat(pattern);

Date myDate = df.parse("2011-08-12T20:17:46.384Z");

(2) If you don't care the date and time and just want to treat the information as a moment in nanoseconds, then you can use Instant:

// The ISO format without zone ID is Instant's default.
// There is no need to pass any format.
Instant ins = Instant.parse("2011-08-12T20:17:46.384Z");

Compare two Byte Arrays? (Java)

Since I wanted to compare two arrays for a unit Test and I arrived on this answer I thought I could share.

You can also do it with:

@Test
public void testTwoArrays() {
  byte[] array = new BigInteger("1111000011110001", 2).toByteArray();
  byte[] secondArray = new BigInteger("1111000011110001", 2).toByteArray();

  Assert.assertArrayEquals(array, secondArray);
}

And you could check on Comparing arrays in JUnit assertions for more infos.

Get everything after the dash in a string in JavaScript

How I would do this:

// function you can use:
function getSecondPart(str) {
    return str.split('-')[1];
}
// use the function:
alert(getSecondPart("sometext-20202"));

Chart won't update in Excel (2007)

What worked for me was using a macro to insert/remove a column in the data table for the chart. This will cause the chart to update the data selection.

I found this to be the fastest way to fix it.

Get table column names in MySQL?

this worked for me..

$sql = "desc MyTableName";
$result = @mysql_query($sql);
while($row = @mysql_fetch_array($result)){
    echo $row[0]."<br>";
}

Auto line-wrapping in SVG text

The following code is working fine. Run the code snippet what it does.

Maybe it can be cleaned up or make it automatically work with all text tags in SVG.

_x000D_
_x000D_
function svg_textMultiline() {_x000D_
_x000D_
  var x = 0;_x000D_
  var y = 20;_x000D_
  var width = 360;_x000D_
  var lineHeight = 10;_x000D_
  _x000D_
  _x000D_
_x000D_
  /* get the text */_x000D_
  var element = document.getElementById('test');_x000D_
  var text = element.innerHTML;_x000D_
_x000D_
  /* split the words into array */_x000D_
  var words = text.split(' ');_x000D_
  var line = '';_x000D_
_x000D_
  /* Make a tspan for testing */_x000D_
  element.innerHTML = '<tspan id="PROCESSING">busy</tspan >';_x000D_
_x000D_
  for (var n = 0; n < words.length; n++) {_x000D_
    var testLine = line + words[n] + ' ';_x000D_
    var testElem = document.getElementById('PROCESSING');_x000D_
    /*  Add line in testElement */_x000D_
    testElem.innerHTML = testLine;_x000D_
    /* Messure textElement */_x000D_
    var metrics = testElem.getBoundingClientRect();_x000D_
    testWidth = metrics.width;_x000D_
_x000D_
    if (testWidth > width && n > 0) {_x000D_
      element.innerHTML += '<tspan x="0" dy="' + y + '">' + line + '</tspan>';_x000D_
      line = words[n] + ' ';_x000D_
    } else {_x000D_
      line = testLine;_x000D_
    }_x000D_
  }_x000D_
  _x000D_
  element.innerHTML += '<tspan x="0" dy="' + y + '">' + line + '</tspan>';_x000D_
  document.getElementById("PROCESSING").remove();_x000D_
  _x000D_
}_x000D_
_x000D_
_x000D_
svg_textMultiline();
_x000D_
body {_x000D_
  font-family: arial;_x000D_
  font-size: 20px;_x000D_
}_x000D_
svg {_x000D_
  background: #dfdfdf;_x000D_
  border:1px solid #aaa;_x000D_
}_x000D_
svg text {_x000D_
  fill: blue;_x000D_
  stroke: red;_x000D_
  stroke-width: 0.3;_x000D_
  stroke-linejoin: round;_x000D_
  stroke-linecap: round;_x000D_
}
_x000D_
<svg height="300" width="500" xmlns="http://www.w3.org/2000/svg" version="1.1">_x000D_
_x000D_
  <text id="test" y="0">GIETEN - Het college van Aa en Hunze is in de fout gegaan met het weigeren van een zorgproject in het failliete hotel Braams in Gieten. Dat stelt de PvdA-fractie in een brief aan het college. De partij wil opheldering over de kwestie en heeft schriftelijke_x000D_
    vragen ingediend. Verkeerde route De PvdA vindt dat de gemeenteraad eerst gepolst had moeten worden, voordat het college het plan afwees. "Volgens ons is de verkeerde route gekozen", zegt PvdA-raadslid Henk Santes.</text>_x000D_
_x000D_
</svg>
_x000D_
_x000D_
_x000D_

jQuery select change show/hide div event

<script>  
$(document).ready(function(){
    $('#colorselector').on('change', function() {
      if ( this.value == 'red')
      {
        $("#divid").show();
      }
      else
      {
        $("#divid").hide();
      }
    });
});
</script>

Do like this for every value Also change the values... as per your parameters

php search array key and get value

The key is already the ... ehm ... key

echo $array[20120504];

If you are unsure, if the key exists, test for it

$key = 20120504;
$result = isset($array[$key]) ? $array[$key] : null;

Minor addition:

$result = @$array[$key] ?: null;

One may argue, that @ is bad, but keep it serious: This is more readable and straight forward, isn't?

Update: With PHP7 my previous example is possible without the error-silencer

$result = $array[$key] ?? null;

PHP: How to send HTTP response code?

We can get different return value from http_response_code via the two different environment:

  1. Web Server Environment
  2. CLI environment

At the web server environment, return previous response code if you provided a response code or when you do not provide any response code then it will be print the current value. Default value is 200 (OK).

At CLI Environment, true will be return if you provided a response code and false if you do not provide any response_code.

Example of Web Server Environment of Response_code's return value:

var_dump(http_respone_code(500)); // int(200)
var_dump(http_response_code()); // int(500)

Example of CLI Environment of Response_code's return value:

var_dump(http_response_code()); // bool(false)
var_dump(http_response_code(501)); // bool(true)
var_dump(http_response_code()); // int(501)

Class JavaLaunchHelper is implemented in two places

You can find all the details here:

  • IDEA-170117 "objc: Class JavaLaunchHelper is implemented in both ..." warning in Run consoles

It's the old bug in Java on Mac that got triggered by the Java Agent being used by the IDE when starting the app. This message is harmless and is safe to ignore. Oracle developer's comment:

The message is benign, there is no negative impact from this problem since both copies of that class are identical (compiled from the exact same source). It is purely a cosmetic issue.

The problem is fixed in Java 9 and in Java 8 update 152.

If it annoys you or affects your apps in any way (it shouldn't), the workaround for IntelliJ IDEA is to disable idea_rt launcher agent by adding idea.no.launcher=true into idea.properties (Help | Edit Custom Properties...). The workaround will take effect on the next restart of the IDE.

I don't recommend disabling IntelliJ IDEA launcher agent, though. It's used for such features as graceful shutdown (Exit button), thread dumps, workarounds a problem with too long command line exceeding OS limits, etc. Losing these features just for the sake of hiding the harmless message is probably not worth it, but it's up to you.

How to send a header using a HTTP request through a curl call?

I use Postman.

Execute whatever call you want to do. Then, postman provides a handy tool to show the curl code .

Run it in the terminal. enter image description here

enter image description here

Updating a dataframe column in spark

Commonly when updating a column, we want to map an old value to a new value. Here's a way to do that in pyspark without UDF's:

# update df[update_col], mapping old_value --> new_value
from pyspark.sql import functions as F
df = df.withColumn(update_col,
    F.when(df[update_col]==old_value,new_value).
    otherwise(df[update_col])).

CSS values using HTML5 data attribute

As of today, you can read some values from HTML5 data attributes in CSS3 declarations. In CaioToOn's fiddle the CSS code can use the data properties for setting the content.

Unfortunately it is not working for the width and height (tested in Google Chrome 35, Mozilla Firefox 30 & Internet Explorer 11).

But there is a CSS3 attr() Polyfill from Fabrice Weinberg which provides support for data-width and data-height. You can find the GitHub repo to it here: cssattr.js.

Truncate number to two decimal places without rounding

This worked well for me. I hope it will fix your issues too.

function toFixedNumber(number) {
    const spitedValues = String(number.toLocaleString()).split('.');
    let decimalValue = spitedValues.length > 1 ? spitedValues[1] : '';
    decimalValue = decimalValue.concat('00').substr(0,2);

    return '$'+spitedValues[0] + '.' + decimalValue;
}

// 5.56789      ---->  $5.56
// 0.342        ---->  $0.34
// -10.3484534  ---->  $-10.34 
// 600          ---->  $600.00

_x000D_
_x000D_
function convertNumber(){_x000D_
  var result = toFixedNumber(document.getElementById("valueText").value);_x000D_
  document.getElementById("resultText").value = result;_x000D_
}_x000D_
_x000D_
_x000D_
function toFixedNumber(number) {_x000D_
        const spitedValues = String(number.toLocaleString()).split('.');_x000D_
        let decimalValue = spitedValues.length > 1 ? spitedValues[1] : '';_x000D_
        decimalValue = decimalValue.concat('00').substr(0,2);_x000D_
_x000D_
        return '$'+spitedValues[0] + '.' + decimalValue;_x000D_
}
_x000D_
<div>_x000D_
  <input type="text" id="valueText" placeholder="Input value here..">_x000D_
  <br>_x000D_
  <button onclick="convertNumber()" >Convert</button>_x000D_
  <br><hr>_x000D_
  <input type="text" id="resultText" placeholder="result" readonly="true">_x000D_
</div>
_x000D_
_x000D_
_x000D_

The meaning of NoInitialContextException error

you need to put the following name/value pairs into a hash table and call this constructor:

public InitialContext(Hashtable<?,?> environment)

the exact values depend on your application server, this example is for jboss

jndi.java.naming.provider.url=jnp://localhost:1099/
jndi.java.naming.factory.url=org.jboss.naming:org.jnp.interfaces
jndi.java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory

What does "Changes not staged for commit" mean

Remove dir/.../.git

works for me.

Change status bar color with AppCompat ActionBarActivity

I don't think the status bar color has been implemented in AppCompat yet. These are the attributes which are available:

    <!-- ============= -->
    <!-- Color palette -->
    <!-- ============= -->

    <!-- The primary branding color for the app. By default, this is the color applied to the
         action bar background. -->
    <attr name="colorPrimary" format="color" />

    <!-- Dark variant of the primary branding color. By default, this is the color applied to
         the status bar (via statusBarColor) and navigation bar (via navigationBarColor). -->
    <attr name="colorPrimaryDark" format="color" />

    <!-- Bright complement to the primary branding color. By default, this is the color applied
         to framework controls (via colorControlActivated). -->
    <attr name="colorAccent" format="color" />

    <!-- The color applied to framework controls in their normal state. -->
    <attr name="colorControlNormal" format="color" />

    <!-- The color applied to framework controls in their activated (ex. checked) state. -->
    <attr name="colorControlActivated" format="color" />

    <!-- The color applied to framework control highlights (ex. ripples, list selectors). -->
    <attr name="colorControlHighlight" format="color" />

    <!-- The color applied to framework buttons in their normal state. -->
    <attr name="colorButtonNormal" format="color" />

    <!-- The color applied to framework switch thumbs in their normal state. -->
    <attr name="colorSwitchThumbNormal" format="color" />

(From \sdk\extras\android\support\v7\appcompat\res\values\attrs.xml)

How to add item to the beginning of List<T>?

Since .NET 4.7.1, you can use the side-effect free Prepend() and Append(). The output is going to be an IEnumerable.

// Creating an array of numbers
var ti = new List<int> { 1, 2, 3 };

// Prepend and Append any value of the same type
var results = ti.Prepend(0).Append(4);

// output is 0, 1, 2, 3, 4
Console.WriteLine(string.Join(", ", results ));

Hexadecimal To Decimal in Shell Script

To convert from hex to decimal, there are many ways to do it in the shell or with an external program:

With :

$ echo $((16#FF))
255

with :

$ echo "ibase=16; FF" | bc
255

with :

$ perl -le 'print hex("FF");'
255

with :

$ printf "%d\n" 0xFF
255

with :

$ python -c 'print(int("FF", 16))'
255

with :

$ ruby -e 'p "FF".to_i(16)'
255

with :

$ nodejs <<< "console.log(parseInt('FF', 16))"
255

with :

$ rhino<<EOF
print(parseInt('FF', 16))
EOF
...
255

with :

$ groovy -e 'println Integer.parseInt("FF",16)'
255

Android: How to create a Dialog without a title?

After a bunch of hacking, I got this to work:

            Window window = dialog.getWindow();
            View view = window.getDecorView();
            final int topPanelId = getResources().getIdentifier( "topPanel", "id", "android" );
            LinearLayout topPanel = (LinearLayout) view.findViewById(topPanelId);
            topPanel.setVisibility(View.GONE);

Create a new txt file using VB.NET

You could just use this

FileOpen(1, "C:\my files\2010\SomeFileName.txt", OpenMode.Output)
FileClose(1)

This opens the file replaces whatever is in it and closes the file.

Setting new value for an attribute using jQuery

Works fine for me

See example here. http://jsfiddle.net/blowsie/c6VAy/

Make sure your jquery is inside $(document).ready function or similar.

Also you can improve your code by using jquery data

$('#amount').data('min','1000');

<div id="amount" data-min=""></div>

Update,

A working example of your full code (pretty much) here. http://jsfiddle.net/blowsie/c6VAy/3/

How to avoid .pyc files?

Starting with Python 3.8 you can use the environment variable PYTHONPYCACHEPREFIX to define a cache directory for Python.

From the Python docs:

If this is set, Python will write .pyc files in a mirror directory tree at this path, instead of in pycache directories within the source tree. This is equivalent to specifying the -X pycache_prefix=PATH option.

Example

If you add the following line to your ./profile in Linux:

export PYTHONPYCACHEPREFIX="$HOME/.cache/cpython/"

Python won't create the annoying __pycache__ directories in your project directory, instead it will put all of them under ~/.cache/cpython/

(change) vs (ngModelChange) in angular

As I have found and wrote in another topic - this applies to angular < 7 (not sure how it is in 7+)

Just for the future

we need to observe that [(ngModel)]="hero.name" is just a short-cut that can be de-sugared to: [ngModel]="hero.name" (ngModelChange)="hero.name = $event".

So if we de-sugar code we would end up with:

<select (ngModelChange)="onModelChange()" [ngModel]="hero.name" (ngModelChange)="hero.name = $event">

or

<[ngModel]="hero.name" (ngModelChange)="hero.name = $event" select (ngModelChange)="onModelChange()">

If you inspect the above code you will notice that we end up with 2 ngModelChange events and those need to be executed in some order.

Summing up: If you place ngModelChange before ngModel, you get the $event as the new value, but your model object still holds previous value. If you place it after ngModel, the model will already have the new value.

SOURCE

IF a cell contains a string

You can use OR() to group expressions (as well as AND()):

=IF(OR(condition1, condition2), true, false)

=IF(AND(condition1, condition2), true, false)

So if you wanted to test for "cat" and "22":

=IF(AND(SEARCH("cat",a1),SEARCH("22",a1)),"cat and 22","none")

Set the intervals of x-axis using r

You can use axis:

> axis(side=1, at=c(0:23))

That is, something like this:

plot(0:23, d, type='b', axes=FALSE)
axis(side=1, at=c(0:23))
axis(side=2, at=seq(0, 600, by=100))
box()

How to my "exe" from PyCharm project

You cannot directly save a Python file as an exe and expect it to work -- the computer cannot automatically understand whatever code you happened to type in a text file. Instead, you need to use another program to transform your Python code into an exe.

I recommend using a program like Pyinstaller. It essentially takes the Python interpreter and bundles it with your script to turn it into a standalone exe that can be run on arbitrary computers that don't have Python installed (typically Windows computers, since Linux tends to come pre-installed with Python).

To install it, you can either download it from the linked website or use the command:

pip install pyinstaller

...from the command line. Then, for the most part, you simply navigate to the folder containing your source code via the command line and run:

pyinstaller myscript.py

You can find more information about how to use Pyinstaller and customize the build process via the documentation.


You don't necessarily have to use Pyinstaller, though. Here's a comparison of different programs that can be used to turn your Python code into an executable.

Git pushing to remote branch

First, let's note that git push "wants" two more arguments and will make them up automatically if you don't supply them. The basic command is therefore git push remote refspec.

The remote part is usually trivial as it's almost always just the word origin. The trickier part is the refspec. Most commonly, people write a branch name here: git push origin master, for instance. This uses your local branch to push to a branch of the same name1 on the remote, creating it if necessary. But it doesn't have to be just a branch name.

In particular, a refspec has two colon-separated parts. For git push, the part on the left identifies what to push,2 and the part on the right identifies the name to give to the remote. The part on the left in this case would be branch_name and the part on the right would be branch_name_test. For instance:

git push origin foo:foo_test

As you are doing the push, you can tell your git push to set your branch's upstream name at the same time, by adding -u to the git push options. Setting the upstream name makes your git save the foo_test (or whatever) name, so that a future git push with no arguments, while you're on the foo branch, can try to push to foo_test on the remote (git also saves the remote, origin in this case, so that you don't have to enter that either).

You need only pass -u once: it basically just runs git branch --set-upstream-to for you. (If you pass -u again later, it re-runs the upstream-setting, changing it as directed; or you can run git branch --set-upstream-to yourself.)

However, if your git is 2.0 or newer, and you have not set any special configuration, you will run into the same kind of thing that had me enter footnote 1 above: push.default will be set to simple, which will refuse to push because the upstream's name differs from your own local name. If you set push.default to upstream, git will stop complaining—but the simplest solution is just to rename your local branch first, so that the local and remote names match. (What settings to set, and/or whether to rename your branch, are up to you.)


1More precisely, git consults your remote.remote.push setting to derive the upstream half of the refspec. If you haven't set anything here, the default is to use the same name.

2This doesn't have to be a branch name. For instance, you can supply HEAD, or a commit hash, here. If you use something other than a branch name, you may have to spell out the full refs/heads/branch on the right, though (it depends on what names are already on the remote).

Rails: Default sort order for a rails model?

default_scope

This works for Rails 4+:

class Book < ActiveRecord::Base
  default_scope { order(created_at: :desc) }
end

For Rails 2.3, 3, you need this instead:

default_scope order('created_at DESC')

For Rails 2.x:

default_scope :order => 'created_at DESC'

Where created_at is the field you want the default sorting to be done on.

Note: ASC is the code to use for Ascending and DESC is for descending (desc, NOT dsc !).

scope

Once you're used to that you can also use scope:

class Book < ActiveRecord::Base
  scope :confirmed, :conditions => { :confirmed => true }
  scope :published, :conditions => { :published => true }
end

For Rails 2 you need named_scope.

:published scope gives you Book.published instead of Book.find(:published => true).

Since Rails 3 you can 'chain' those methods together by concatenating them with periods between them, so with the above scopes you can now use Book.published.confirmed.

With this method, the query is not actually executed until actual results are needed (lazy evaluation), so 7 scopes could be chained together but only resulting in 1 actual database query, to avoid performance problems from executing 7 separate queries.

You can use a passed in parameter such as a date or a user_id (something that will change at run-time and so will need that 'lazy evaluation', with a lambda, like this:

scope :recent_books, lambda 
  { |since_when| where("created_at >= ?", since_when) }
  # Note the `where` is making use of AREL syntax added in Rails 3.

Finally you can disable default scope with:

Book.with_exclusive_scope { find(:all) } 

or even better:

Book.unscoped.all

which will disable any filter (conditions) or sort (order by).

Note that the first version works in Rails2+ whereas the second (unscoped) is only for Rails3+


So ... if you're thinking, hmm, so these are just like methods then..., yup, that's exactly what these scopes are!
They are like having def self.method_name ...code... end but as always with ruby they are nice little syntactical shortcuts (or 'sugar') to make things easier for you!

In fact they are Class level methods as they operate on the 1 set of 'all' records.

Their format is changing however, with rails 4 there are deprecation warning when using #scope without passing a callable object. For example scope :red, where(color: 'red') should be changed to scope :red, -> { where(color: 'red') }.

As a side note, when used incorrectly, default_scope can be misused/abused.
This is mainly about when it gets used for actions like where's limiting (filtering) the default selection (a bad idea for a default) rather than just being used for ordering results.
For where selections, just use the regular named scopes. and add that scope on in the query, e.g. Book.all.published where published is a named scope.

In conclusion, scopes are really great and help you to push things up into the model for a 'fat model thin controller' DRYer approach.

How do I POST with multipart form data using fetch?

You're setting the Content-Type to be multipart/form-data, but then using JSON.stringify on the body data, which returns application/json. You have a content type mismatch.

You will need to encode your data as multipart/form-data instead of json. Usually multipart/form-data is used when uploading files, and is a bit more complicated than application/x-www-form-urlencoded (which is the default for HTML forms).

The specification for multipart/form-data can be found in RFC 1867.

For a guide on how to submit that kind of data via javascript, see here.

The basic idea is to use the FormData object (not supported in IE < 10):

async function sendData(url, data) {
  const formData  = new FormData();

  for(const name in data) {
    formData.append(name, data[name]);
  }

  const response = await fetch(url, {
    method: 'POST',
    body: formData
  });

  // ...
}

Per this article make sure not to set the Content-Type header. The browser will set it for you, including the boundary parameter.

keycloak Invalid parameter: redirect_uri

Your redirect URI in your code(keycloak.init) should be the same as the redirect URI set on Keycloak server (client -> Valid Uri) click to view image of my code click to view my keycloak settings

Notice: Undefined offset: 0 in

its just a warning use:

error_reporting(0);

it shows when we do not initialize array and direct assigning value to indexes.

somefunction{
$raja[0]="this";
$raja[1]="that";
}

instead :

somefunction{
$raja=array(0=>'this',1='that');
//or
$raja=array("this","that");
}

it just notification, do not generate any output error or any unexpected output.

Flutter: RenderBox was not laid out

I had a similir problem, but in my case, I put a row in the leading of the ListView, and it was consuming all the space, of course. I just had to take the Row out of the leading, and it was solved. I would recommend to check if the problem is a larger widget than its container can have.

Expanded(child:MyListView())

Selecting fields from JSON output

Assume you stored that dictionary in a variable called values. To get id in to a variable, do:

idValue = values['criteria'][0]['id']

If that json is in a file, do the following to load it:

import json
jsonFile = open('your_filename.json', 'r')
values = json.load(jsonFile)
jsonFile.close()

If that json is from a URL, do the following to load it:

import urllib, json
f = urllib.urlopen("http://domain/path/jsonPage")
values = json.load(f)
f.close()

To print ALL of the criteria, you could:

for criteria in values['criteria']:
    for key, value in criteria.iteritems():
        print key, 'is:', value
    print ''

How can I increment a char?

def doubleChar(str):
    result = ''
    for char in str:
        result += char * 2
    return result

print(doubleChar("amar"))

output:

aammaarr

How to disable JavaScript in Chrome Developer Tools?

Click the ? menu in the corner of the Developer Tools, click Settings, then check Disable Javascript under Debugger.

How to change the window title of a MATLAB plotting figure?

First you must create an empty figure with the following command.

figure('name','Title of the window here');

By doing this, the newly created figure becomes you active figure. Immediately after calling a plot() command, it will print your plotting onto this figure. So your window will have a title.

This is the code you must use:

figure('name','Title of the window here');

hold on

x = [0; 0.2; 0.4; 0.6; 0.8; 1; 1.2; 1.4; 1.6; 1.8; 2; 2.2; 2.4; 2.6; 2.8; 3; 3.2; 3.4; 3.6; 3.8; 4; 4.2; 4.4; 4.6; 4.8; 5; 5.2; 5.4; 5.6; 5.8; 6; 6.2; 6.4; 6.6; 6.8; 7; 7.2; 7.4; 7.6; 7.8; 8; 8.2; 8.4; 8.6; 8.8; 9; 9.2; 9.4; 9.6; 9.8; 10; 10.2; 10.4; 10.6; 10.8; 11; 11.2; 11.4; 11.6; 11.8; 12; 12.2; 12.4; 12.6; 12.8; 13; 13.2; 13.4; 13.6; 13.8; 14; 14.2; 14.4; 14.6; 14.8; 15; 15.2; 15.4; 15.6; 15.8; 16; 16.2; 16.4; 16.6; 16.8; 17; 17.2; 17.4; 17.6; 17.8; 18; 18.2; 18.4; 18.6; 18.8];
y = [0; 0.198669; 0.389418; 0.564642; 0.717356; 0.841471; 0.932039; 0.98545; 0.999574; 0.973848; 0.909297; 0.808496; 0.675463; 0.515501; 0.334988; 0.14112; -0.0583741; -0.255541; -0.44252; -0.611858; -0.756802; -0.871576; -0.951602; -0.993691; -0.996165; -0.958924; -0.883455; -0.772764; -0.631267; -0.464602; -0.279415; -0.0830894; 0.116549; 0.311541; 0.494113; 0.656987; 0.793668; 0.898708; 0.96792; 0.998543; 0.989358; 0.940731; 0.854599; 0.734397; 0.584917; 0.412118; 0.22289; 0.0247754; -0.174327; -0.366479; -0.544021; -0.699875; -0.827826; -0.922775; -0.980936; -0.99999; -0.979178; -0.919329; -0.822829; -0.693525; -0.536573; -0.358229; -0.165604; 0.033623; 0.23151; 0.420167; 0.592074; 0.740376; 0.859162; 0.943696; 0.990607; 0.998027; 0.965658; 0.894791; 0.788252; 0.650288; 0.486399; 0.303118; 0.107754; -0.0919069; -0.287903; -0.472422; -0.638107; -0.778352; -0.887567; -0.961397; -0.9969; -0.992659; -0.948844; -0.867202; -0.750987; -0.604833; -0.434566; -0.246974; -0.0495356];
plot(x, y, '--b');

x = [0; 0.2; 0.4; 0.6; 0.8; 1; 1.2; 1.4; 1.6; 1.8; 2; 2.2; 2.4; 2.6; 2.8; 3; 3.2; 3.4; 3.6; 3.8; 4; 4.2; 4.4; 4.6; 4.8; 5; 5.2; 5.4; 5.6; 5.8; 6; 6.2; 6.4; 6.6; 6.8; 7; 7.2; 7.4; 7.6; 7.8; 8; 8.2; 8.4; 8.6; 8.8; 9; 9.2; 9.4; 9.6; 9.8; 10; 10.2; 10.4; 10.6; 10.8; 11; 11.2; 11.4; 11.6; 11.8; 12; 12.2; 12.4; 12.6; 12.8; 13; 13.2; 13.4; 13.6; 13.8; 14; 14.2; 14.4; 14.6; 14.8; 15; 15.2; 15.4; 15.6; 15.8; 16; 16.2; 16.4; 16.6; 16.8; 17; 17.2; 17.4; 17.6; 17.8; 18; 18.2; 18.4; 18.6; 18.8];
y = [-1; -0.980133; -0.921324; -0.825918; -0.697718; -0.541836; -0.364485; -0.172736; 0.0257666; 0.223109; 0.411423; 0.583203; 0.731599; 0.850695; 0.935744; 0.983355; 0.991629; 0.960238; 0.890432; 0.784994; 0.648128; 0.48529; 0.302972; 0.108443; -0.0905427; -0.286052; -0.470289; -0.635911; -0.776314; -0.885901; -0.960303; -0.996554; -0.993208; -0.950399; -0.869833; -0.754723; -0.609658; -0.44042; -0.253757; -0.057111; 0.141679; 0.334688; 0.514221; 0.673121; 0.805052; 0.904756; 0.968256; 0.993023; 0.978068; 0.923987; 0.832937; 0.708548; 0.555778; 0.380717; 0.190346; -0.00774649; -0.205663; -0.395514; -0.56973; -0.721365; -0.844375; -0.933855; -0.986238; -0.999436; -0.972923; -0.907755; -0.806531; -0.673287; -0.513333; -0.333047; -0.139617; 0.0592467; 0.255615; 0.44166; 0.609964; 0.753818; 0.867487; 0.946439; 0.987526; 0.989111; 0.95113; 0.875097; 0.764044; 0.622398; 0.455806; 0.27091; 0.0750802; -0.123876; -0.318026; -0.499631; -0.66145; -0.797032; -0.900972; -0.969126; -0.998776];
plot(x, y, '-r');

hold off

title('My plot title');
xlabel('My x-axis title');
ylabel('My y-axis title');

How do you validate a URL with a regular expression in Python?

urlparse quite happily takes invalid URLs, it is more a string string-splitting library than any kind of validator. For example:

from urlparse import urlparse
urlparse('http://----')
# returns: ParseResult(scheme='http', netloc='----', path='', params='', query='', fragment='')

Depending on the situation, this might be fine..

If you mostly trust the data, and just want to verify the protocol is HTTP, then urlparse is perfect.

If you want to make the URL is actually a legal URL, use the ridiculous regex

If you want to make sure it's a real web address,

import urllib
try:
    urllib.urlopen(url)
except IOError:
    print "Not a real URL"

Maven home (M2_HOME) not being picked up by IntelliJ IDEA

If M2_HOME is configured to point to the Maven home directory then:

  1. Go to File -> Settings
  2. Search for Maven
  3. Select Runner
  4. Insert in the field VM Options the following string:

    Dmaven.multiModuleProjectDirectory=$M2_HOME
    

Click Apply and OK

How can I output leading zeros in Ruby?

As stated by the other answers, "%03d" % number works pretty well, but it goes against the rubocop ruby style guide:

Favor the use of sprintf and its alias format over the fairly cryptic String#% method

We can obtain the same result in a more readable way using the following:

format('%03d', number)

How to determine if .NET Core is installed

The correct answer for runtime-only environments without the SDK, such as a server with the Windows Hosting package installed, is to run PowerShell with the following command:

dotnet --info

Per the official documentation:

  • The --version option "Prints out the version of the .NET Core SDK in use." and therefore doesn't work if the SDK is not installed. Whereas...
  • The --info option "Prints out detailed information about the CLI tooling and the environment, such as the current operating system, commit SHA for the version, and other information."

Here's another official article explaining how .NET Core versioning works. :)

Nginx: stat() failed (13: permission denied)

You can also add which user will run the nginx. In the nginx.conf file, make the following changes:

user root;

You can add the above line as the first line in your nginx conf. You can write the name of any user who has the permission to write in that directory.

How to take last four characters from a varchar?

tested solution on hackerrank....

select distinct(city) from station
where substr(lower(city), length(city), 1) in ('a', 'e', 'i', 'o', 'u') and substr(lower(city), 1, 1) in ('a', 'e', 'i', 'o', 'u');

Converting HTML string into DOM elements?

Here is a little code that is useful.

var uiHelper = function () {

var htmls = {};

var getHTML = function (url) {
                /// <summary>Returns HTML in a string format</summary>
                /// <param name="url" type="string">The url to the file with the HTML</param>

    if (!htmls[url])
    {
    var xmlhttp = new XMLHttpRequest();
    xmlhttp.open("GET", url, false);
    xmlhttp.send();
    htmls[url] = xmlhttp.responseText;
     };
     return htmls[url];
    };

        return {
            getHTML: getHTML
        };
}();

--Convert the HTML string into a DOM Element

String.prototype.toDomElement = function () {

        var wrapper = document.createElement('div');
        wrapper.innerHTML = this;
        var df= document.createDocumentFragment();
        return df.addChilds(wrapper.children);
};

--prototype helper

HTMLElement.prototype.addChilds = function (newChilds) {
        /// <summary>Add an array of child elements</summary>
        /// <param name="newChilds" type="Array">Array of HTMLElements to add to this HTMLElement</param>
        /// <returns type="this" />
        for (var i = 0; i < newChilds.length; i += 1) { this.appendChild(newChilds[i]); };
        return this;
};

--Usage

 thatHTML = uiHelper.getHTML('/Scripts/elevation/ui/add/html/add.txt').toDomElement();

Mocking member variables of a class using Mockito

Yes, this can be done, as the following test shows (written with the JMockit mocking API, which I develop):

@Test
public void testFirst(@Mocked final Second sec) {
    new NonStrictExpectations() {{ sec.doSecond(); result = "Stubbed Second"; }};

    First first = new First();
    assertEquals("Stubbed Second", first.doSecond());
}

With Mockito, however, such a test cannot be written. This is due to the way mocking is implemented in Mockito, where a subclass of the class to be mocked is created; only instances of this "mock" subclass can have mocked behavior, so you need to have the tested code use them instead of any other instance.

Removing index column in pandas when reading a csv

DataFrames and Series always have an index. Although it displays alongside the column(s), it is not a column, which is why del df['index'] did not work.

If you want to replace the index with simple sequential numbers, use df.reset_index().

To get a sense for why the index is there and how it is used, see e.g. 10 minutes to Pandas.

Finding all objects that have a given property inside a collection

Sounds a lot like something you would use LINQ for in .NET

While there's no "real" LINQ implementation for java yet, you might want to have a look at Quaere which could do what you describe easily enough.

pass post data with window.location.href

Short answer: no. window.location.href is not capable of passing POST data.

Somewhat more satisfying answer: You can use this function to clone all your form data and submit it.

var submitMe = document.createElement("form");
submitMe.action = "YOUR_URL_HERE"; // Remember to change me
submitMe.method = "post";
submitMe.enctype = "multipart/form-data";
var nameJoiner = "_";
// ^ The string used to join form name and input name
//   so that you can differentiate between forms when
//   processing the data server-side.
submitMe.importFields = function(form){
    for(k in form.elements){
        if(input = form.elements[k]){
            if(input.type!="submit"&&
                     (input.nodeName=="INPUT"
                    ||input.nodeName=="TEXTAREA"
                    ||input.nodeName=="BUTTON"
                    ||input.nodeName=="SELECT")
                     ){
                var output = input.cloneNode(true);
                output.name = form.name + nameJoiner + input.name;
                this.appendChild(output);
            }
        }
    }
}
  • Do submitMe.importFields(form_element); for each of the three forms you want to submit.
  • This function will add each form's name to the names of its child inputs (If you have an <input name="email"> in <form name="login">, the submitted name will be login_name.
  • You can change the nameJoiner variable to something other than _ so it doesn't conflict with your input naming scheme.
  • Once you've imported all the necessary forms, do submitMe.submit();

Regular Expression to match string starting with a specific word

If you wish to match only lines beginning with stop use

^stop

If you wish to match lines beginning with the word stop followed by a space

^stop\s

Or, if you wish to match lines beginning with the word stop but followed by either a space or any other non word character you can use (your regex flavor permitting)

^stop\W

On the other hand, what follows matches a word at the beginning of a string on most regex flavors (in these flavors \w matches the opposite of \W)

^\w

If your flavor does not have the \w shortcut, you can use

^[a-zA-Z0-9]+

Be wary that this second idiom will only match letters and numbers, no symbol whatsoever.

Check your regex flavor manual to know what shortcuts are allowed and what exactly do they match (and how do they deal with Unicode.)

How to pass payload via JSON file for curl?

curl sends POST requests with the default content type of application/x-www-form-urlencoded. If you want to send a JSON request, you will have to specify the correct content type header:

$ curl -vX POST http://server/api/v1/places.json -d @testplace.json \
--header "Content-Type: application/json"

But that will only work if the server accepts json input. The .json at the end of the url may only indicate that the output is json, it doesn't necessarily mean that it also will handle json input. The API documentation should give you a hint on whether it does or not.

The reason you get a 401 and not some other error is probably because the server can't extract the auth_token from your request.

How do I declare and assign a variable on a single line in SQL

You've nearly got it:

DECLARE @myVariable nvarchar(max) = 'hello world';

See here for the docs

For the quotes, SQL Server uses apostrophes, not quotes:

DECLARE @myVariable nvarchar(max) = 'John said to Emily "Hey there Emily"';

Use double apostrophes if you need them in a string:

DECLARE @myVariable nvarchar(max) = 'John said to Emily ''Hey there Emily''';

PHP array value passes to next row

Change the checkboxes so that the name includes the index inside the brackets:

<input type="checkbox" class="checkbox_veh" id="checkbox_addveh<?php echo $i; ?>" <?php if ($vehicle_feature[$i]->check) echo "checked"; ?> name="feature[<?php echo $i; ?>]" value="<?php echo $vehicle_feature[$i]->id; ?>"> 

The checkboxes that aren't checked are never submitted. The boxes that are checked get submitted, but they get numbered consecutively from 0, and won't have the same indexes as the other corresponding input fields.

How to get first N number of elements from an array

Do not try doing that using a map function. Map function should be used to map values from one thing to other. When the number of input and output match.

In this case use filter function which is also available on the array. Filter function is used when you want to selectively take values maching certain criteria. Then you can write your code like

var items = list
             .filter((i, index) => (index < 3))
             .map((i, index) => {
                   return (
                     <myview item={i} key={i.id} />
                   );
              });

Redirecting to a new page after successful login

First of all, move all your PHP code to the top. Without it, my code below wont work.

To do the redirect, use:

header('Location: http://www.example.com/');

Also, please consider my advice. Since it's not the first question today and all your questions are related to basics, you should consider reading some good PHP book to understand how things work.

Here you can find useful links to free books: https://stackoverflow.com/tags/php/info

Toad for Oracle..How to execute multiple statements?

Wrap the multiple statements in a BEGIN END block to make them one statement and add a slash after the END; clause.

BEGIN
  insert into books
  (id, title, author)
  values
  (books_seq.nextval, 'The Bite in the Apple', 'Chrisann Brennan');

  insert into books
  (id, title, author)
  values
  (books_seq.nextval, 'The Restaurant at the End of the Universe', 'Douglas Adams');
END;
/

That way, it is just ctrl-a then ctrl-enter and it goes.

Git branching: master vs. origin/master vs. remotes/origin/master

  1. origin - This is a custom and most common name to point to remote.

$ git remote add origin https://github.com/git/git.git --- You will run this command to link your github project to origin. Here origin is user-defined. You can rename it by $ git remote rename old-name new-name


  1. master - The default branch name in Git is master. For both remote and local computer.

  1. origin/master - This is just a pointer to refer master branch in remote repo. Remember i said origin points to remote.

$ git fetch origin - Downloads objects and refs from remote repository to your local computer [origin/master]. That means it will not affect your local master branch unless you merge them using $ git merge origin/master. Remember to checkout the correct branch where you need to merge before run this command

Note: Fetched content is represented as a remote branch. Fetch gives you a chance to review changes before integrating them into your copy of the project. To show changes between yours and remote $git diff master..origin/master

How do I remove an array item in TypeScript?

let departments is an array. You want to remove an item from this array.

departments: string[] = [];

 removeDepartment(name: string): void {
    this.departments = this.departments.filter(item => item != name);
  }

How to `wget` a list of URLs in a text file?

try:

wget -i text_file.txt

(check man wget)

Android Studio Image Asset Launcher Icon Background Color

the above approach didn't work for me on Android Studio 3.0. It still shows the background. I just made an empty background file

<?xml version="1.0" encoding="utf-8"?>
<vector
android:height="108dp"
android:width="108dp"
android:viewportHeight="108"
android:viewportWidth="108"
xmlns:android="http://schemas.android.com/apk/res/android">
</vector>

This worked except the full bleed layers

Unix ls command: show full path when using options

I use this command:

ls -1 | xargs readlink -f

Why does the C preprocessor interpret the word "linux" as the constant "1"?

In the Old Days (pre-ANSI), predefining symbols such as unix and vax was a way to allow code to detect at compile time what system it was being compiled for. There was no official language standard back then (beyond the reference material at the back of the first edition of K&R), and C code of any complexity was typically a complex maze of #ifdefs to allow for differences between systems. These macro definitions were generally set by the compiler itself, not defined in a library header file. Since there were no real rules about which identifiers could be used by the implementation and which were reserved for programmers, compiler writers felt free to use simple names like unix and assumed that programmers would simply avoid using those names for their own purposes.

The 1989 ANSI C standard introduced rules restricting what symbols an implementation could legally predefine. A macro predefined by the compiler could only have a name starting with two underscores, or with an underscore followed by an uppercase letter, leaving programmers free to use identifiers not matching that pattern and not used in the standard library.

As a result, any compiler that predefines unix or linux is non-conforming, since it will fail to compile perfectly legal code that uses something like int linux = 5;.

As it happens, gcc is non-conforming by default -- but it can be made to conform (reasonably well) with the right command-line options:

gcc -std=c90 -pedantic ... # or -std=c89 or -ansi
gcc -std=c99 -pedantic
gcc -std=c11 -pedantic

See the gcc manual for more details.

gcc will be phasing out these definitions in future releases, so you shouldn't write code that depends on them. If your program needs to know whether it's being compiled for a Linux target or not it can check whether __linux__ is defined (assuming you're using gcc or a compiler that's compatible with it). See the GNU C preprocessor manual for more information.

A largely irrelevant aside: the "Best One Liner" winner of the 1987 International Obfuscated C Code Contest, by David Korn (yes, the author of the Korn Shell) took advantage of the predefined unix macro:

main() { printf(&unix["\021%six\012\0"],(unix)["have"]+"fun"-0x60);}

It prints "unix", but for reasons that have absolutely nothing to do with the spelling of the macro name.

How to scroll the window using JQuery $.scrollTo() function

To get around the html vs body issue, I fixed this by not animating the css directly but rather calling window.scrollTo(); on each step:

$({myScrollTop:window.pageYOffset}).animate({myScrollTop:300}, {
  duration: 600,
  easing: 'swing',
  step: function(val) {
    window.scrollTo(0, val);
  }
});

This works nicely without any refresh gotchas as it's using cross-browser JavaScript.

Have a look at http://james.padolsey.com/javascript/fun-with-jquerys-animate/ for more information on what you can do with jQuery's animate function.

How can I flush GPU memory using CUDA (physical reset is unavailable)

for the ones using python:

import torch, gc
gc.collect()
torch.cuda.empty_cache()

Get Date Object In UTC format in Java

tl;dr

Instant.ofEpochMilli ( 1_393_572_325_000L )
       .toString()

2014-02-28T07:25:25Z

Details

(a) You seem be confused as to what a Date is. As the answer by JB Nizet said, a Date tracks the number of milliseconds since the Unix epoch (first moment of 1970) in the UTC time zone (that is, with no time zone offset). So a Date has no time zone. And it has no "format". We create string representations from a Date's value, but the Date itself is not a String and has no String.

(b) You refer to a "UTC format". UTC is not a format, not I have heard of. UTC (Coordinated Universal Time) is the origin point of time zones. Time zones east of the Royal Observatory in Greenwich, London are some number of hours & minutes ahead of UTC. Westward time zones are behind UTC.

You seem to be referring to ISO 8601 formatted strings. You are using the optional format, omitting (1) the T from the middle, and (2) the offset-from-UTC at the end. Unless presenting the string to a user in the user interface of your app, I suggest you generally stick with the usual format:

  • 2014-02-27T23:03:14+05:30
  • 2014-02-27T23:03:14Z ('Z' for Zulu, or UTC, with an offset of +00:00)

(c) Avoid the 3 or 4 letter time zone codes. They are neither standardized nor unique. "IST" for example can mean either Indian Standard Time or Irish Standard Time.

(d) Put some effort into searching StackOverflow before posting. You would have found all your answers.

(e) Avoid the java.util.Date & Calendar classes bundled with Java. They are notoriously troublesome. Use either the Joda-Time library or Java 8’s new java.time package (inspired by Joda-Time, defined by JSR 310).

java.time

The java.time classes use standard ISO 8601 formats by default when parsing and generating strings.

OffsetDateTime odt = OffsetDateTime.parse( "2014-02-27T23:03:14+05:30" ); 
Instant instant = Instant.parse( "2014-02-27T23:03:14Z" );

Parse your count of milliseconds since the epoch of first moment of 1970 in UTC.

Instant instant = Instant.ofEpochMilli ( 1_393_572_325_000L );

instant.toString(): 2014-02-28T07:25:25Z

Adjust that Instant into a desired time zone.

ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = instant.atZone( z );

zdt.toString(): 2014-02-28T02:25:25-05:00[America/Montreal]


About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.


Joda-Time

UPDATE: The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

Joda-Time uses ISO 8601 as its defaults.

A Joda-Time DateTime object knows its on assigned time zone, unlike a java.util.Date object.

Generally better to specify a time zone explicitly rather than rely on default time zone.

Example Code

long input = 1393572325000L;
DateTime dateTimeUtc = new DateTime( input, DateTimeZone.UTC );

DateTimeZone timeZoneIndia = DateTimeZone.forID( "Asia/Kolkata" );
DateTimeZone timeZoneIreland = DateTimeZone.forID( "Europe/Dublin" );

DateTime dateTimeIndia = dateTimeUtc.withZone( timeZoneIndia );
DateTime dateTimeIreland = dateTimeIndia.withZone( timeZoneIreland );

// Use a formatter to create a String representation. The formatter can adjust time zone if you so desire.
DateTimeFormatter formatter = DateTimeFormat.forStyle( "FM" ).withLocale( Locale.CANADA_FRENCH ).withZone( DateTimeZone.forID( "America/Montreal" ) );
String output = formatter.print( dateTimeIreland );

Dump to console…

// All three of these date-time objects represent the *same* moment in the timeline of the Universe.
System.out.println( "dateTimeUtc: " + dateTimeUtc );
System.out.println( "dateTimeIndia: " + dateTimeIndia );
System.out.println( "dateTimeIreland: " + dateTimeIreland );

System.out.println( "output for Montréal: " + output );

When run…

dateTimeUtc: 2014-02-28T07:25:25.000Z
dateTimeIndia: 2014-02-28T12:55:25.000+05:30
dateTimeIreland: 2014-02-28T07:25:25.000Z
output for Montréal: vendredi 28 février 2014 02:25:25

Actually, java.util.Date does have a time zone. That time zone is assigned deep in its source code. Yet the class ignores that time zone for most practical purposes. And its toString method applies the JVM’s current default time zone rather than that internal time zone. Confusing? Yes. This is one of many reasons to avoid the old java.util.Date/.Calendar classes. Use java.time and/or Joda-Time instead.

How to modify JsonNode in Java?

I think you can just cast to ObjectNode and use put method. Like this

ObjectNode o = (ObjectNode) jsonNode; o.put("value", "NO");

How to delete large data of table in SQL without log?

  1. If you are Deleting All the rows in that table the simplest option is to Truncate table, something like

    TRUNCATE TABLE LargeTable
    GO
    

    Truncate table will simply empty the table, you cannot use WHERE clause to limit the rows being deleted and no triggers will be fired.

  2. On the other hand if you are deleting more than 80-90 Percent of the data, say if you have total of 11 Million rows and you want to delete 10 million another way would be to Insert these 1 million rows (records you want to keep) to another staging table. Truncate this Large table and Insert back these 1 Million rows.

  3. Or if permissions/views or other objects which has this large table as their underlying table doesnt get affected by dropping this table you can get these relatively small amount of the rows into another table drop this table and create another table with same schema and import these rows back into this ex-Large table.

  4. One last option I can think of is to change your database's Recovery Mode to SIMPLE and then delete rows in smaller batches using a while loop something like this..

    DECLARE @Deleted_Rows INT;
    SET @Deleted_Rows = 1;
    
    
    WHILE (@Deleted_Rows > 0)
      BEGIN
       -- Delete some small number of rows at a time
         DELETE TOP (10000)  LargeTable 
         WHERE readTime < dateadd(MONTH,-7,GETDATE())
    
      SET @Deleted_Rows = @@ROWCOUNT;
    END
    

and dont forget to change the Recovery mode back to full and I think you have to take a backup to make it fully affective (the change or recovery modes).

Formatting numbers (decimal places, thousands separators, etc) with CSS

No, you have to use javascript once it's in the DOM or format it via your language server-side (PHP/ruby/python etc.)

How can I change Eclipse theme?

In the eclipse Version: 2019-09 R (4.13.0) on windows Go to Window > preferences > Appearance Select the required theme for dark theme to choose Dark and click on Ok. enter image description here

C# Telnet Library

Another one, it is an older project but shares the complete source code: http://telnetcsharp.codeplex.com/

Short IF - ELSE statement

The ternary operator can only be the right side of an assignment and not a statement of its own.

http://www.devdaily.com/java/edu/pj/pj010018/

How to reset selected file with input tag file type in Angular 2?

I am using a a very simple aproach. After a file has been uploaded, i shortly remove the input control, using *ngIf. That will cause the input field being removed from the dom and re-added, consequencely it is a new control, and therefore it is emply:

_x000D_
_x000D_
showUploader: boolean = true;

async upload($event) {
  await dosomethingwiththefile();
  this.showUploader = false;
  setTimeout(() =>{ this.showUploader = true }, 100);
}
_x000D_
<input type="file" (change)="upload($event)" *ngIf="showUploader">
_x000D_
_x000D_
_x000D_

Equivalent of Super Keyword in C#

C# equivalent of your code is

  class Imagedata : PDFStreamEngine
  {
     // C# uses "base" keyword whenever Java uses "super" 
     // so instead of super(...) in Java we should call its C# equivalent (base):
     public Imagedata()
       : base(ResourceLoader.loadProperties("org/apache/pdfbox/resources/PDFTextStripper.properties", true)) 
     { }

     // Java methods are virtual by default, when C# methods aren't.
     // So we should be sure that processOperator method in base class 
     // (that is PDFStreamEngine)
     // declared as "virtual"
     protected override void processOperator(PDFOperator operations, List arguments)
     {
        base.processOperator(operations, arguments);
     }
  }

Get all photos from Instagram which have a specific hashtag with PHP

To get more than 20 you can use a load more button.

index.php

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8" />
  <title>Instagram more button example</title>
  <!--
    Instagram PHP API class @ Github
    https://github.com/cosenary/Instagram-PHP-API
  -->
  <style>
    article, aside, figure, footer, header, hgroup, 
    menu, nav, section { display: block; }
    ul {
      width: 950px;
    }
    ul > li {
      float: left;
      list-style: none;
      padding: 4px;
    }
    #more {
      bottom: 8px;
      margin-left: 80px;
      position: fixed;
      font-size: 13px;
      font-weight: 700;
      line-height: 20px;
    }
  </style>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
  <script>
    $(document).ready(function() {
      $('#more').click(function() {
        var tag   = $(this).data('tag'),
            maxid = $(this).data('maxid');

        $.ajax({
          type: 'GET',
          url: 'ajax.php',
          data: {
            tag: tag,
            max_id: maxid
          },
          dataType: 'json',
          cache: false,
          success: function(data) {
            // Output data
            $.each(data.images, function(i, src) {
              $('ul#photos').append('<li><img src="' + src + '"></li>');
            });

            // Store new maxid
            $('#more').data('maxid', data.next_id);
          }
        });
      });
    });
  </script>
</head>
<body>

<?php
  /**
   * Instagram PHP API
   */

   require_once 'instagram.class.php';

    // Initialize class with client_id
    // Register at http://instagram.com/developer/ and replace client_id with your own
    $instagram = new Instagram('ENTER CLIENT ID HERE');

    // Get latest photos according to geolocation for Växjö
    // $geo = $instagram->searchMedia(56.8770413, 14.8092744);

    $tag = 'sweden';

    // Get recently tagged media
    $media = $instagram->getTagMedia($tag);

    // Display first results in a <ul>
    echo '<ul id="photos">';

    foreach ($media->data as $data) 
    {
        echo '<li><img src="'.$data->images->thumbnail->url.'"></li>';
    }
    echo '</ul>';

    // Show 'load more' button
    echo '<br><button id="more" data-maxid="'.$media->pagination->next_max_id.'" data-tag="'.$tag.'">Load more ...</button>';
?>

</body>
</html>

ajax.php

<?php
    /**
     * Instagram PHP API
     */

     require_once 'instagram.class.php';

      // Initialize class for public requests
      $instagram = new Instagram('ENTER CLIENT ID HERE');

      // Receive AJAX request and create call object
      $tag = $_GET['tag'];
      $maxID = $_GET['max_id'];
      $clientID = $instagram->getApiKey();

      $call = new stdClass;
      $call->pagination->next_max_id = $maxID;
      $call->pagination->next_url = "https://api.instagram.com/v1/tags/{$tag}/media/recent?client_id={$clientID}&max_tag_id={$maxID}";

      // Receive new data
      $media = $instagram->getTagMedia($tag,$auth=false,array('max_tag_id'=>$maxID));

      // Collect everything for json output
      $images = array();
      foreach ($media->data as $data) {
        $images[] = $data->images->thumbnail->url;
      }

      echo json_encode(array(
        'next_id' => $media->pagination->next_max_id,
        'images'  => $images
      ));
?>

instagram.class.php

Find the function getTagMedia() and replace with:

public function getTagMedia($name, $auth=false, $params=null) {
    return $this->_makeCall('tags/' . $name . '/media/recent', $auth, $params);
}

What is let-* in Angular 2 templates?

update Angular 5

ngOutletContext was renamed to ngTemplateOutletContext

See also https://github.com/angular/angular/blob/master/CHANGELOG.md#500-beta5-2017-08-29

original

Templates (<template>, or <ng-template> since 4.x) are added as embedded views and get passed a context.

With let-col the context property $implicit is made available as col within the template for bindings. With let-foo="bar" the context property bar is made available as foo.

For example if you add a template

<ng-template #myTemplate let-col let-foo="bar">
  <div>{{col}}</div>
  <div>{{foo}}</div>
</ng-template>

<!-- render above template with a custom context -->
<ng-template [ngTemplateOutlet]="myTemplate"
             [ngTemplateOutletContext]="{
                                           $implicit: 'some col value',
                                           bar: 'some bar value'
                                        }"
></ng-template>

See also this answer and ViewContainerRef#createEmbeddedView.

*ngFor also works this way. The canonical syntax makes this more obvious

<ng-template ngFor let-item [ngForOf]="items" let-i="index" let-odd="odd">
  <div>{{item}}</div>
</ng-template>

where NgFor adds the template as embedded view to the DOM for each item of items and adds a few values (item, index, odd) to the context.

See also Using $implict to pass multiple parameters

Issue pushing new code in Github

I got this error on Azure Git, and this solves the problem:

git fetch
git pull
git push --no-verify

phpMyAdmin - can't connect - invalid setings - ever since I added a root password - locked out

I had this same problem using the Windows XAMPP 1.7.4 -- after setting a password for mysql, I could no longer access phpMyAdmin. I changed the password in config.inc.php from ' ' to the new mysql password, and changed AllowNoPassword from true to false. I still couldn't log in.

However, I saw that there is also a config.inc.php.safe file, and when I also edited the password settings in THAT file I was subsequently able to log in to phpMyAdmin.

Remove carriage return in Unix

Once more a solution... Because there's always one more:

perl -i -pe 's/\r//' filename

It's nice because it's in place and works in every flavor of unix/linux I've worked with.

Get an object attribute

If you need to fetch an object's property dynamically, use the getattr() function: getattr(user, "fullName") - or to elaborate:

user = User()
property = "fullName"
name = getattr(user, property)

Otherwise just use user.fullName.

Setting HttpContext.Current.Session in a unit test

I found the following simple solution for specifying a user in the HttpContext: https://forums.asp.net/post/5828182.aspx

Select rows having 2 columns equal value

For question 1:

SELECT DISTINCT a.*
  FROM [Table] a
  INNER JOIN
  [Table] b
  ON
  a.C1 <> b.C1 AND a.C2 = b.C2 AND a.C3 = b.C3 AND a.C4 = b.C4

Using an inner join is much more efficient than a subquery because it requires fewer operations, and maintains the use of indexes when comparing the values, allowing the SQL server to better optimize the query before its run. Using appropriate indexes with this query can bring your query down to only n * log(n) rows to compare.

Using a subquery with your where clause or only doing a standard join where C1 does not equal C2 results in a table that has roughly 2 to the power of n rows to compare, where n is the number of rows in the table.

So by using proper indexing with an Inner Join, which only returns records which met the join criteria, we're able to drastically improve the performance. Also note that we return DISTINCT a.*, because this will only return the columns for table a where the join criteria was met. Returning * would return the columns for both a and b where the criteria was met, and not including DISTINCT would result in a duplicate of each row for each time that row row matched another row more than once.

A similar approach could also be performed using CROSS APPLY, which still uses a subquery, but makes use of indexes more efficiently.

An implementation with the keyword USING instead of ON could also work, but the syntax is more complicated to make work because your want to match on rows where C1 does not match, so you would need an additional where clause to filter out matching each row with itself. Also, USING is not compatible/allowed in conjunction with table values in all implementations of SQL, so it's best to stick with ON.

Similarly, for question 2:

SELECT DISTINCT a.*
  FROM [Table] a
  INNER JOIN
  [Table] b
  ON
  a.C1 <> b.C1 AND a.C4 = b.C4

This is essentially the same query as for 1, but because it only wants to know which rows match for C4, we only compare on the rows for C4.

How can I exclude multiple folders using Get-ChildItem -exclude?

The exclusion pattern should be case-insensitive, so you shouldn't have to specify every case for the exclusion.

That said, the -Exclude parameter accepts an array of strings, so as long as you define $archive as such, you should be set.

$archive = ("*archive*","*Archive*","*ARCHIVE*");

You also should drop the trailing asterisk from $folder - since you're specifying -recurse, you should only need to give the top-level folder.

$folder = "T:\Drawings\Design\"

Fully revised script. This also changes how you detect whether you've found a directory, and skips the Foreach-Object because you can just pull the property directly & dump it all to the file.

$folder = "T:\Drawings\Design\";
$raw_txt = "T:\Design Projects\Design_Admin\PowerShell\raw.txt";
$search_pro = "T:\Design Projects\Design_Admin\PowerShell\search.pro";
$archive = ("*archive*","*Archive*","*ARCHIVE*");

Get-ChildItem -Path $folder -Exclude $archive -Recurse  | where {$_.PSIsContainer}  | select-Object -expandproperty FullName |out-file $search_pro 

What are some uses of template template parameters?

In the solution with variadic templates provided by pfalcon, I found it difficult to actually specialize the ostream operator for std::map due to the greedy nature of the variadic specialization. Here's a slight revision which worked for me:

#include <iostream>
#include <vector>
#include <deque>
#include <list>
#include <map>

namespace containerdisplay
{
  template<typename T, template<class,class...> class C, class... Args>
  std::ostream& operator <<(std::ostream& os, const C<T,Args...>& objs)
  {
    std::cout << __PRETTY_FUNCTION__ << '\n';
    for (auto const& obj : objs)
      os << obj << ' ';
    return os;
  }  
}

template< typename K, typename V>
std::ostream& operator << ( std::ostream& os, 
                const std::map< K, V > & objs )
{  

  std::cout << __PRETTY_FUNCTION__ << '\n';
  for( auto& obj : objs )
  {    
    os << obj.first << ": " << obj.second << std::endl;
  }

  return os;
}


int main()
{

  {
    using namespace containerdisplay;
    std::vector<float> vf { 1.1, 2.2, 3.3, 4.4 };
    std::cout << vf << '\n';

    std::list<char> lc { 'a', 'b', 'c', 'd' };
    std::cout << lc << '\n';

    std::deque<int> di { 1, 2, 3, 4 };
    std::cout << di << '\n';
  }

  std::map< std::string, std::string > m1 
  {
      { "foo", "bar" },
      { "baz", "boo" }
  };

  std::cout << m1 << std::endl;

    return 0;
}

RequiredIf Conditional Validation Attribute

Expanding on the notes from Adel Mourad and Dan Hunex, I amended the code to provide an example that only accepts values that do not match the given value.

I also found that I didn't need the JavaScript.

I added the following class to my Models folder:

public class RequiredIfNotAttribute : ValidationAttribute, IClientValidatable
{
    private String PropertyName { get; set; }
    private Object InvalidValue { get; set; }
    private readonly RequiredAttribute _innerAttribute;

    public RequiredIfNotAttribute(String propertyName, Object invalidValue)
    {
        PropertyName = propertyName;
        InvalidValue = invalidValue;
        _innerAttribute = new RequiredAttribute();
    }

    protected override ValidationResult IsValid(object value, ValidationContext context)
    {
        var dependentValue = context.ObjectInstance.GetType().GetProperty(PropertyName).GetValue(context.ObjectInstance, null);

        if (dependentValue.ToString() != InvalidValue.ToString())
        {
            if (!_innerAttribute.IsValid(value))
            {
                return new ValidationResult(FormatErrorMessage(context.DisplayName), new[] { context.MemberName });
            }
        }
        return ValidationResult.Success;
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule
        {
            ErrorMessage = ErrorMessageString,
            ValidationType = "requiredifnot",
        };
        rule.ValidationParameters["dependentproperty"] = (context as ViewContext).ViewData.TemplateInfo.GetFullHtmlFieldId(PropertyName);
        rule.ValidationParameters["invalidvalue"] = InvalidValue is bool ? InvalidValue.ToString().ToLower() : InvalidValue;

        yield return rule;
    }

I didn't need to make any changes to my view, but did make a change to the properties of my model:

    [RequiredIfNot("Id", 0, ErrorMessage = "Please select a Source")]
    public string TemplateGTSource { get; set; }

    public string TemplateGTMedium
    {
        get
        {
            return "Email";
        }
    }

    [RequiredIfNot("Id", 0, ErrorMessage = "Please enter a Campaign")]
    public string TemplateGTCampaign { get; set; }

    [RequiredIfNot("Id", 0, ErrorMessage = "Please enter a Term")]
    public string TemplateGTTerm { get; set; }

Hope this helps!

How do I uniquely identify computers visiting my web site?

I would do this using a combination of cookies and flash cookies. Create a GUID and store it in a cookie. If the cookie doesn't exist, try to read it from the flash cookie. If it's still not found, create it and write it to the flash cookie. This way you can share the same GUID across browsers.

C# Checking if button was clicked

Click is an event that fires immediately after you release the mouse button. So if you want to check in the handler for button2.Click if button1 was clicked before, all you could do is have a handler for button1.Click which sets a bool flag of your own making to true.

private bool button1WasClicked = false;

private void button1_Click(object sender, EventArgs e)
{
    button1WasClicked = true;
}

private void button2_Click(object sender, EventArgs e)
{
    if (textBox2.Text == textBox3.Text && button1WasClicked)
    { 
        StreamWriter myWriter = File.CreateText(@"c:\Program Files\text.txt");
        myWriter.WriteLine(textBox1.Text);
        myWriter.WriteLine(textBox2.Text);
        button1WasClicked = false;
    }
}

How can I access "static" class variables within class methods in Python?

Define class method:

class Foo(object):
    bar = 1
    @classmethod
    def bah(cls):    
        print cls.bar

Now if bah() has to be instance method (i.e. have access to self), you can still directly access the class variable.

class Foo(object):
    bar = 1
    def bah(self):    
        print self.bar

PHP - syntax error, unexpected T_CONSTANT_ENCAPSED_STRING

When you're working with strings in PHP you'll need to pay special attention to the formation, using " or '

$string = 'Hello, world!';
$string = "Hello, world!";

Both of these are valid, the following is not:

$string = "Hello, world';

You must also note that ' inside of a literal started with " will not end the string, and vice versa. So when you have a string which contains ', it is generally best practice to use double quotation marks.

$string = "It's ok here";

Escaping the string is also an option

$string = 'It\'s ok here too';

More information on this can be found within the documentation

what does it mean "(include_path='.:/usr/share/pear:/usr/share/php')"?

Thats just the directories showing you where PHP was looking for your file. Make sure that cron1.php exists where you think it does. And make sure you know where dirname(__FILE__) and $_SERVER['DOCUMENT_ROOT'] are pointing where you'd expect.

This value can be adjusted in your php.ini file.

How should I import data from CSV into a Postgres table using pgAdmin 3?

You may have a table called 'test'

COPY test(gid, "name", the_geom)
FROM '/home/data/sample.csv'
WITH DELIMITER ','
CSV HEADER

Creating a new user and password with Ansible

Just for completeness I will post the ad-hoc command using ansible since there is a catch there as well.

First try generating an encrypted password using the mkpasswd utility that is available on most Linux systems:

mkpasswd --method=SHA-512

Then try the ansible ad-hock command:

ansible all -m user -a 'name=testuser shell=/bin/bash \
     comment="Test User" password=$6$XXXX' -k -u admin --sudo

But make sure:

  1. The command is in single quotes and NOT double otherwise your password will never work
  2. You run it with --sudo or you end up with an error like (useradd: cannot lock /etc/passwd; try again later)

Deactivate or remove the scrollbar on HTML

This makes it so if before there was a scrollbar then it makes it so the scrollbar has a display of none so you can't see it anymore. You can replace html to body or a class or ID. Hope it works for you :)

html::-webkit-scrollbar {
    display: none;
}

how to configure lombok in eclipse luna

Step 1: Create a maven project in Eclipse and add the below dependency in the pom.xml

<dependencies>
  <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.16.18</version>
</dependency>

Step 2: Run As --> Configuraitons --> Goto Arguments --> give arguments like below maven -clean install

enter image description here

Step 3: Run As --> maven clean

Once you do the maven clean you see Build Success and lombok jar file in the maven Dependencies

enter image description here

Step 4: Goto the jar location as shown in the below screen shot.

enter image description here

Step 5: Give command as shown like below after reaching in the .m2 folder

enter image description here

Step 6: Locate where is your eclipse folder once you this window.Once you see Install Successfull message click on Quit Installer option at the bottom.

enter image description here

Step 7 : We have finished installing the lombok.jar successfully .Now restart your Eclipse IDE and Start below Sample Code to check whether the data is coming or not in the getters and setters.

Step 8: Open Eclipse and create simple Java Maven project and see in the Outline section you can see getters and setters are created you can use either @Data or @Getter @Setter On top of class or you can give on top of variable

@Getter @Setter
privateString riverName;

{OR}

@Getter
@Setter
Class River{
String riverName;
}

[OR]

@Data
class River 
{
Private String riverName;

}

You can see the project structure and Outline Structure how it got created in simple steps.

enter image description here

Fitting a Normal distribution to 1D data

There is a much simpler way to do it using seaborn:

import seaborn as sns
from scipy.stats import norm

data = norm.rvs(5,0.4,size=1000) # you can use a pandas series or a list if you want

sns.distplot(data)
plt.show()

output:

enter image description here

for more information:seaborn.distplot

Remove all special characters from a string

Update

The solution below has a "SEO friendlier" version:

function hyphenize($string) {
    $dict = array(
        "I'm"      => "I am",
        "thier"    => "their",
        // Add your own replacements here
    );
    return strtolower(
        preg_replace(
          array( '#[\\s-]+#', '#[^A-Za-z0-9. -]+#' ),
          array( '-', '' ),
          // the full cleanString() can be downloaded from http://www.unexpectedit.com/php/php-clean-string-of-utf8-chars-convert-to-similar-ascii-char
          cleanString(
              str_replace( // preg_replace can be used to support more complicated replacements
                  array_keys($dict),
                  array_values($dict),
                  urldecode($string)
              )
          )
        )
    );
}

function cleanString($text) {
    $utf8 = array(
        '/[áàâãªä]/u'   =>   'a',
        '/[ÁÀÂÃÄ]/u'    =>   'A',
        '/[ÍÌÎÏ]/u'     =>   'I',
        '/[íìîï]/u'     =>   'i',
        '/[éèêë]/u'     =>   'e',
        '/[ÉÈÊË]/u'     =>   'E',
        '/[óòôõºö]/u'   =>   'o',
        '/[ÓÒÔÕÖ]/u'    =>   'O',
        '/[úùûü]/u'     =>   'u',
        '/[ÚÙÛÜ]/u'     =>   'U',
        '/ç/'           =>   'c',
        '/Ç/'           =>   'C',
        '/ñ/'           =>   'n',
        '/Ñ/'           =>   'N',
        '/–/'           =>   '-', // UTF-8 hyphen to "normal" hyphen
        '/[’‘‹›‚]/u'    =>   ' ', // Literally a single quote
        '/[“”«»„]/u'    =>   ' ', // Double quote
        '/ /'           =>   ' ', // nonbreaking space (equiv. to 0x160)
    );
    return preg_replace(array_keys($utf8), array_values($utf8), $text);
}

The rationale for the above functions (which I find way inefficient - the one below is better) is that a service that shall not be named apparently ran spelling checks and keyword recognition on the URLs.

After losing a long time on a customer's paranoias, I found out they were not imagining things after all -- their SEO experts [I am definitely not one] reported that, say, converting "Viaggi Economy Perù" to viaggi-economy-peru "behaved better" than viaggi-economy-per (the previous "cleaning" removed UTF8 characters; Bogotà became bogot, Medellìn became medelln and so on).

There were also some common misspellings that seemed to influence the results, and the only explanation that made sense to me is that our URL were being unpacked, the words singled out, and used to drive God knows what ranking algorithms. And those algorithms apparently had been fed with UTF8-cleaned strings, so that "Perù" became "Peru" instead of "Per". "Per" did not match and sort of took it in the neck.

In order to both keep UTF8 characters and replace some misspellings, the faster function below became the more accurate (?) function above. $dict needs to be hand tailored, of course.

Previous answer

A simple approach:

// Remove all characters except A-Z, a-z, 0-9, dots, hyphens and spaces
// Note that the hyphen must go last not to be confused with a range (A-Z)
// and the dot, NOT being special (I know. My life was a lie), is NOT escaped

$str = preg_replace('/[^A-Za-z0-9. -]/', '', $str);

// Replace sequences of spaces with hyphen
$str = preg_replace('/  */', '-', $str);

// The above means "a space, followed by a space repeated zero or more times"
// (should be equivalent to / +/)

// You may also want to try this alternative:
$str = preg_replace('/\\s+/', '-', $str);

// where \s+ means "zero or more whitespaces" (a space is not necessarily the
// same as a whitespace) just to be sure and include everything

Note that you might have to first urldecode() the URL, since %20 and + both are actually spaces - I mean, if you have "Never%20gonna%20give%20you%20up" you want it to become Never-gonna-give-you-up, not Never20gonna20give20you20up . You might not need it, but I thought I'd mention the possibility.

So the finished function along with test cases:

function hyphenize($string) {
    return 
    ## strtolower(
          preg_replace(
            array('#[\\s-]+#', '#[^A-Za-z0-9. -]+#'),
            array('-', ''),
        ##     cleanString(
              urldecode($string)
        ##     )
        )
    ## )
    ;
}

print implode("\n", array_map(
    function($s) {
            return $s . ' becomes ' . hyphenize($s);
    },
    array(
    'Never%20gonna%20give%20you%20up',
    "I'm not the man I was",
    "'Légeresse', dit sa majesté",
    )));


Never%20gonna%20give%20you%20up    becomes  never-gonna-give-you-up
I'm not the man I was              becomes  im-not-the-man-I-was
'Légeresse', dit sa majesté        becomes  legeresse-dit-sa-majeste

To handle UTF-8 I used a cleanString implementation found online (link broken since, but a stripped down copy with all the not-too-esoteric UTF8 characters is at the beginning of the answer; it's also easy to add more characters to it if you need) that converts UTF8 characters to normal characters, thus preserving the word "look" as much as possible. It could be simplified and wrapped inside the function here for performance.

The function above also implements converting to lowercase - but that's a taste. The code to do so has been commented out.

SQL Current month/ year question

How about:

Select *
from some_table st
where st.month = to_char(sysdate,'MM') and
    st.year = to_char(sysdate,'YYYY');

should work in Oracle. What database are you using? I ask because not all databases have the same date functions.

How do I set <table> border width with CSS?

<table style="border: 5px solid black">

This only adds a border around the table.

If you want same border through CSS then add this rule:

table tr td { border: 5px solid black; }

and one thing for HTML table to avoid spaces

<table cellspacing="0" cellpadding="0">

C# Form.Close vs Form.Dispose

As a general rule, I'd always advocate explicitly calling the Dispose method for any class that offers it, either by calling the method directly or wrapping in a "using" block.

Most often, classes that implement IDisposible do so because they wrap some unmanaged resource that needs to be freed. While these classes should have finalizers that act as a safeguard, calling Dispose will help free that memory earlier and with lower overhead.

In the case of the Form object, as the link fro Kyra noted, the Close method is documented to invoke Dispose on your behalf so you need not do so explicitly. However, to me, that has always felt like relying on an implementaion detail. I prefer to always call both Close and Dispose for classes that implement them, to guard against implementation changes/errors and for the sake of being clear. A properly implemented Dispose method should be safe to invoke multiple times.

How do I update a Linq to SQL dbml file?

You could also check out the PLINQO set of code generation templates, based on CodeSmith, which allow you to do a lot of neat things for and with Linq-to-SQL:

  • generate one file per class (instead of a single, huge file)
  • update your model as needed
  • many more features

Check out the PLINQO site at http://www.plinqo.com and have a look at the intro videos.

The second tool I know of are the Huagati DBML/EDMX tools, which allow update of DBML (Linq-to-SQL) and EDMX (Entity Framework) mapping files, and more (like naming conventions etc.).

Marc

What is the "Illegal Instruction: 4" error and why does "-mmacosx-version-min=10.x" fix it?

I got this error when attempting to build with Xcode 10. It appears to be a bug in the Swift compiler. Building with Whole Module Optimization on, resolves the issue: https://forums.swift.org/t/illegal-instruction-4-when-trying-to-compile-project/16118

This is not an ideal solution, I will continue to use Xcode 9.4.1 until this issue is resolved.

How do I get into a Docker container's shell?

Another option is to use nsenter.

PID=$(docker inspect --format {{.State.Pid}} <container_name_or_ID>)
nsenter --target $PID --mount --uts --ipc --net --pid

Mac zip compress without __MACOSX folder?

Another shell script that could be used with the Automator tool (see also benedikt's answer on how to create the script) is:

while read -r f; do
    d="$(dirname "$f")"
    n="$(basename "$f")"
    cd "$d"
    zip "$n.zip" -x \*.DS_Store -r "$n"
done

The difference here is that this code directly compresses selected folders without macOS specific files (and not first compressing and afterwards deleting).

How to remove all white spaces in java

Why not use a regex for this?

a = a.replaceAll("\\s","");

In the context of a regex, \s will remove anything that is a space character (including space, tab characters etc). You need to escape the backslash in Java so the regex turns into \\s. Also, since Strings are immutable it is important that you assign the return value of the regex to a.

Cordova : Requirements check failed for JDK 1.8 or greater

MacOS answer with multiple Java versions installed and no need to uninstall

Show me what versions of Java I have installed :

$ ls -l /Library/Java/JavaVirtualMachines/

To set it to my jdk1.8 version :

$ ln -s /Library/Java/JavaVirtualMachines/jdk1.8.0_261.jdk/Contents/Home/bin/javac /usr/local/bin/javac

To set it to my jdk11 version :

$ ln -s /Library/Java/JavaVirtualMachines/jdk-11.0.7.jdk/Contents/Home/bin/javac /usr/local/bin/javac

-------------------------------------------------------------------------

Note that, despite what the message says, it appears that it means that it wants version 1.8, and throws this message if you have a later version.

What follows is my earlier attempts which lead me to the above answer, which then worked ... You might need to do something different depending on what's installed, so maybe these notes might help :


Set it to my jdk1.8 version

$ export PATH=/Library/Java/JavaVirtualMachines/jdk-11.0.7.jdk/Contents/Home/bin/javac:$PATH

Set it to my jdk11 version

$ export PATH=/Library/Java/JavaVirtualMachines/jdk1.8.0_261.jdk/Contents/Home/bin/javac:$PATH

... but actually that doesn't work because /usr/bin/javac is still what runs first :

$ which javac
/usr/bin/javac

... to see what runs first on the path :

$ cat /etc/paths
/usr/local/bin
/usr/bin
/bin
/usr/sbin
/sbin

That means I can override the /usr/bin/javac ... see the commands at the top of the answer ...
The command to set it to jdk1.8 using ln, at the top of this answer, is what worked for me.

WPF: ItemsControl with scrollbar (ScrollViewer)

You have to modify the control template instead of ItemsPanelTemplate:

<ItemsControl >
    <ItemsControl.Template>
        <ControlTemplate>
            <ScrollViewer x:Name="ScrollViewer" Padding="{TemplateBinding Padding}">
                <ItemsPresenter />
            </ScrollViewer>
        </ControlTemplate>
    </ItemsControl.Template>
</ItemsControl>

Maybe, your code does not working because StackPanel has own scrolling functionality. Try to use StackPanel.CanVerticallyScroll property.

String's Maximum length in Java - calling length() method

Considering the String class' length method returns an int, the maximum length that would be returned by the method would be Integer.MAX_VALUE, which is 2^31 - 1 (or approximately 2 billion.)

In terms of lengths and indexing of arrays, (such as char[], which is probably the way the internal data representation is implemented for Strings), Chapter 10: Arrays of The Java Language Specification, Java SE 7 Edition says the following:

The variables contained in an array have no names; instead they are referenced by array access expressions that use nonnegative integer index values. These variables are called the components of the array. If an array has n components, we say n is the length of the array; the components of the array are referenced using integer indices from 0 to n - 1, inclusive.

Furthermore, the indexing must be by int values, as mentioned in Section 10.4:

Arrays must be indexed by int values;

Therefore, it appears that the limit is indeed 2^31 - 1, as that is the maximum value for a nonnegative int value.

However, there probably are going to be other limitations, such as the maximum allocatable size for an array.

Display a jpg image on a JPanel

I would use a Canvas that I add to the JPanel, and draw the image on the Canvas. But Canvas is a quite heavy object, sine it is from awt.

Any shortcut to initialize all array elements to zero?

While the other answers are correct (int array values are by default initialized to 0), if you wanted to explicitly do so (say for example if you wanted an array filled with the value 42), you can use the fill() method of the Arrays class:

int [] myarray = new int[num_elts];
Arrays.fill(myarray, 42);

Or if you're a fan of 1-liners, you can use the Collections.nCopies() routine:

Integer[] arr = Collections.nCopies(3, 42).toArray(new Integer[0]);

Would give arr the value:

[42, 42, 42]

(though it's Integer, and not int, if you need the primitive type you could defer to the Apache Commons ArrayUtils.toPrimitive() routine:

int [] primarr = ArrayUtils.toPrimitive(arr);

Most efficient way to see if an ArrayList contains an object in Java

Maybe a List isn't what you need.

Maybe a TreeSet would be a better container. You get O(log N) insertion and retrieval, and ordered iteration (but won't allow duplicates).

LinkedHashMap might be even better for your use case, check that out too.

Date vs DateTime

For this, you need to use the date, but ignore the time value.

Ordinarily a date would be a DateTime with time of 00:00:00

The DateTime type has a .Date property which returns the DateTime with the time value set as above.

File Permissions and CHMOD: How to set 777 in PHP upon file creation?

You just need to manually set the desired permissions with chmod():

private function writeFileContent($file, $content){
    $fp = fopen($file, 'w');
    fwrite($fp, $content);
    fclose($fp);

    // Set perms with chmod()
    chmod($file, 0777);
    return true;
}

Error: Generic Array Creation

You can't create arrays with a generic component type.

Create an array of an explicit type, like Object[], instead. You can then cast this to PCB[] if you want, but I don't recommend it in most cases.

PCB[] res = (PCB[]) new Object[list.size()]; /* Not type-safe. */

If you want type safety, use a collection like java.util.List<PCB> instead of an array.

By the way, if list is already a java.util.List, you should use one of its toArray() methods, instead of duplicating them in your code. This doesn't get your around the type-safety problem though.

javascript: optional first argument in function

There is a nice read on Default parameters in ES6 on the MDN website here.
In ES6 you can now do the following:

secondDefaultValue = 'indirectSecondDefaultValue';

function MyObject( param1 = 'firstDefaultValue', param2 = secondDefaultValue ){
    this.first = param1;
    this.second = param2;
}

You can use this also as follows:

var object = new MyObject( undefined, options );

Which will set default value 'firstDefaultValue' for first param1 and your options for second param2.

Here a demonstration in a fiddle

Open a file with Notepad in C#

You are not providing a lot of information, but assuming you want to open just any file on your computer with the application that is specified for the default handler for that filetype, you can use something like this:

var fileToOpen = "SomeFilePathHere";
var process = new Process();
process.StartInfo = new ProcessStartInfo()
{
    UseShellExecute = true,
    FileName = fileToOpen
};

process.Start();
process.WaitForExit();

The UseShellExecute parameter tells Windows to use the default program for the type of file you are opening.

The WaitForExit will cause your application to wait until the application you luanched has been closed.

Can anonymous class implement interface?

Casting anonymous types to interfaces has been something I've wanted for a while but unfortunately the current implementation forces you to have an implementation of that interface.

The best solution around it is having some type of dynamic proxy that creates the implementation for you. Using the excellent LinFu project you can replace

select new
{
  A = value.A,
  B = value.C + "_" + value.D
};

with

 select new DynamicObject(new
 {
   A = value.A,
   B = value.C + "_" + value.D
 }).CreateDuck<DummyInterface>();

How can I set a dynamic model name in AngularJS?

Or you can use

<select [(ngModel)]="Answers[''+question.Name+'']" ng-options="option for option in question.Options">
        </select>

Is "else if" faster than "switch() case"?

Shouldn't be hard to test, create a function that switches or ifelse's between 5 numbers, throw a rand(1,5) into that function and loop that a few times while timing it.

Fatal error: "No Target Architecture" in Visual Studio

Use #include <windows.h> instead of #include <windef.h>.

From the windows.h wikipedia page:

There are a number of child header files that are automatically included with windows.h. Many of these files cannot simply be included by themselves (they are not self-contained), because of dependencies.

windef.h is one of the files automatically included with windows.h.

Jenkins/Hudson - accessing the current build number?

BUILD_NUMBER is the current build number. You can use it in the command you execute for the job, or just use it in the script your job executes.

See the Jenkins documentation for the full list of available environment variables. The list is also available from within your Jenkins instance at http://hostname/jenkins/env-vars.html.

What does ECU units, CPU core and memory mean when I launch a instance

For linuxes I've figured out that ECU could be measured by sysbench:

sysbench --num-threads=128 --test=cpu --cpu-max-prime=50000 --max-requests=50000 run

Total time (t) should be calculated by formula:

ECU=1925/t

And my example test results:

|   instance type   |   time   |   ECU   |
|-------------------|----------|---------|
| m1.small          |  1735,62 |       1 |
| m3.xlarge         |   147,62 |      13 |
| m3.2xlarge        |    74,61 |      26 |
| r3.large          |   295,84 |       7 |
| r3.xlarge         |   148,18 |      13 |
| m4.xlarge         |   146,71 |      13 |
| m4.2xlarge        |    73,69 |      26 |
| c4.xlarge         |   123,59 |      16 |
| c4.2xlarge        |    61,91 |      31 |
| c4.4xlarge        |    31,14 |      62 |

SASS - use variables across multiple files

This answer shows how I ended up using this and the additional pitfalls I hit.

I made a master SCSS file. This file must have an underscore at the beginning for it to be imported:

// assets/_master.scss 
$accent: #6D87A7;           
$error: #811702;

Then, in the header of all of my other .SCSS files, I import the master:

// When importing the master, you leave out the underscore, and it
// will look for a file with the underscore. This prevents the SCSS
// compiler from generating a CSS file from it.
@import "assets/master";

// Then do the rest of my CSS afterwards:
.text { color: $accent; }

IMPORTANT

Do not include anything but variables, function declarations and other SASS features in your _master.scss file. If you include actual CSS, it will duplicate this CSS across every file you import the master into.

HTTPS connections over proxy servers

If it's still of interest, here is an answer to a similar question: Convert HTTP Proxy to HTTPS Proxy in Twisted

To answer the second part of the question:

If yes, what kind of proxy server allows this?

Out of the box, most proxy servers will be configured to allow HTTPS connections only to port 443, so https URIs with custom ports wouldn't work. This is generally configurable, depending on the proxy server. Squid and TinyProxy support this, for example.

Converting Symbols, Accent Letters to English Alphabet

The problem with "converting" arbitrary Unicode to ASCII is that the meaning of a character is culture-dependent. For example, “ß” to a German-speaking person should be converted to "ss" while an English-speaker would probably convert it to “B”.

Add to that the fact that Unicode has multiple code points for the same glyphs.

The upshot is that the only way to do this is create a massive table with each Unicode character and the ASCII character you want to convert it to. You can take a shortcut by normalizing characters with accents to normalization form KD, but not all characters normalize to ASCII. In addition, Unicode does not define which parts of a glyph are "accents".

Here is a tiny excerpt from an app that does this:

switch (c)
{
    case 'A':
    case '\u00C0':  //  À LATIN CAPITAL LETTER A WITH GRAVE
    case '\u00C1':  //  Á LATIN CAPITAL LETTER A WITH ACUTE
    case '\u00C2':  //  Â LATIN CAPITAL LETTER A WITH CIRCUMFLEX
    // and so on for about 20 lines...
        return "A";
        break;

    case '\u00C6'://  Æ LATIN CAPITAL LIGATURE AE
        return "AE";
        break;

    // And so on for pages...
}

How to quickly drop a user with existing privileges

Here's what's finally worked for me :

REVOKE ALL PRIVILEGES ON ALL TABLES IN SCHEMA myschem FROM user_mike;
REVOKE ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA myschem FROM user_mike;
REVOKE ALL PRIVILEGES ON ALL FUNCTIONS IN SCHEMA myschem FROM user_mike;
REVOKE ALL PRIVILEGES ON SCHEMA myschem FROM user_mike;
ALTER DEFAULT PRIVILEGES IN SCHEMA myschem REVOKE ALL ON SEQUENCES FROM user_mike;
ALTER DEFAULT PRIVILEGES IN SCHEMA myschem REVOKE ALL ON TABLES FROM user_mike;
ALTER DEFAULT PRIVILEGES IN SCHEMA myschem REVOKE ALL ON FUNCTIONS FROM user_mike;
REVOKE USAGE ON SCHEMA myschem FROM user_mike;
REASSIGN OWNED BY user_mike TO masteruser;
DROP USER user_mike ;

Default SQL Server Port

The default port 1433 is used when there is only one SQL Server named instance running on the computer.

When multiple SQL Server named instances are running, they run by default under a dynamic port (49152–65535). In this scenario, an application will connect to the SQL Server Browser service port (UDP 1434) to get the dynamic port and then connect to the dynamic port directly.

https://docs.microsoft.com/en-us/sql/sql-server/install/configure-the-windows-firewall-to-allow-sql-server-access

Doing a cleanup action just before Node.js exits

After playing around with other answer, here is my solution for this task. Implementing this way helps me centralize cleanup in one place, preventing double handling the cleanup.

  1. I would like to route all other exiting codes to 'exit' code.
const others = [`SIGINT`, `SIGUSR1`, `SIGUSR2`, `uncaughtException`, `SIGTERM`]
others.forEach((eventType) => {
    process.on(eventType, exitRouter.bind(null, { exit: true }));
})
  1. What the exitRouter does is calling process.exit()
function exitRouter(options, exitCode) {
   if (exitCode || exitCode === 0) console.log(`ExitCode ${exitCode}`);
   if (options.exit) process.exit();
}
  1. On 'exit', handle the clean up with a new function
function exitHandler(exitCode) {
  console.log(`ExitCode ${exitCode}`);
  console.log('Exiting finally...')
}

process.on('exit', exitHandler)

For the demo purpose, this is link to my gist. In the file, i add a setTimeout to fake the process running.

If you run node node-exit-demo.js and do nothing, then after 2 seconds, you see the log:

The service is finish after a while.
ExitCode 0
Exiting finally...

Else if before the service finish, you terminate by ctrl+C, you'll see:

^CExitCode SIGINT
ExitCode 0
Exiting finally...

What happened is the Node process exited initially with code SIGINT, then it routes to process.exit() and finally exited with exit code 0.

View a file in a different Git branch without changing branches

Add the following to your ~/.gitconfig file

[alias]
  cat = "!git show \"$1:$2\" #"

And then try this

git cat BRANCHNAME FILEPATH

Personally I prefer separate parameters without a colon. Why? This choice mirrors the parameters of the checkout command, which I tend to use rather frequently and I find it thus much easier to remember than the bizarro colon-separated parameter of the show command.

Local Storage vs Cookies

In the context of JWTs, Stormpath have written a fairly helpful article outlining possible ways to store them, and the (dis-)advantages pertaining to each method.

It also has a short overview of XSS and CSRF attacks, and how you can combat them.

I've attached some short snippets of the article below, in case their article is taken offline/their site goes down.

Local Storage

Problems:

Web Storage (localStorage/sessionStorage) is accessible through JavaScript on the same domain. This means that any JavaScript running on your site will have access to web storage, and because of this can be vulnerable to cross-site scripting (XSS) attacks. XSS in a nutshell is a type of vulnerability where an attacker can inject JavaScript that will run on your page. Basic XSS attacks attempt to inject JavaScript through form inputs, where the attacker puts alert('You are Hacked'); into a form to see if it is run by the browser and can be viewed by other users.

Prevention:

To prevent XSS, the common response is to escape and encode all untrusted data. But this is far from the full story. In 2015, modern web apps use JavaScript hosted on CDNs or outside infrastructure. Modern web apps include 3rd party JavaScript libraries for A/B testing, funnel/market analysis, and ads. We use package managers like Bower to import other peoples’ code into our apps.

What if only one of the scripts you use is compromised? Malicious JavaScript can be embedded on the page, and Web Storage is compromised. These types of XSS attacks can get everyone’s Web Storage that visits your site, without their knowledge. This is probably why a bunch of organizations advise not to store anything of value or trust any information in web storage. This includes session identifiers and tokens.

As a storage mechanism, Web Storage does not enforce any secure standards during transfer. Whoever reads Web Storage and uses it must do their due diligence to ensure they always send the JWT over HTTPS and never HTTP.

Cookies

Problems:

Cookies, when used with the HttpOnly cookie flag, are not accessible through JavaScript, and are immune to XSS. You can also set the Secure cookie flag to guarantee the cookie is only sent over HTTPS. This is one of the main reasons that cookies have been leveraged in the past to store tokens or session data. Modern developers are hesitant to use cookies because they traditionally required state to be stored on the server, thus breaking RESTful best practices. Cookies as a storage mechanism do not require state to be stored on the server if you are storing a JWT in the cookie. This is because the JWT encapsulates everything the server needs to serve the request.

However, cookies are vulnerable to a different type of attack: cross-site request forgery (CSRF). A CSRF attack is a type of attack that occurs when a malicious web site, email, or blog causes a user’s web browser to perform an unwanted action on a trusted site on which the user is currently authenticated. This is an exploit of how the browser handles cookies. A cookie can only be sent to the domains in which it is allowed. By default, this is the domain that originally set the cookie. The cookie will be sent for a request regardless of whether you are on galaxies.com or hahagonnahackyou.com.

Prevention:

Modern browsers support the SameSite flag, in addition to HttpOnly and Secure. The purpose of this flag is to prevent the cookie from being transmitted in cross-site requests, preventing many kinds of CSRF attack.

For browsers that do not support SameSite, CSRF can be prevented by using synchronized token patterns. This sounds complicated, but all modern web frameworks have support for this.

For example, AngularJS has a solution to validate that the cookie is accessible by only your domain. Straight from AngularJS docs:

When performing XHR requests, the $http service reads a token from a cookie (by default, XSRF-TOKEN) and sets it as an HTTP header (X-XSRF-TOKEN). Since only JavaScript that runs on your domain can read the cookie, your server can be assured that the XHR came from JavaScript running on your domain. You can make this CSRF protection stateless by including a xsrfToken JWT claim:

{
  "iss": "http://galaxies.com",
  "exp": 1300819380,
  "scopes": ["explorer", "solar-harvester", "seller"],
  "sub": "[email protected]",
  "xsrfToken": "d9b9714c-7ac0-42e0-8696-2dae95dbc33e"
}

Leveraging your web app framework’s CSRF protection makes cookies rock solid for storing a JWT. CSRF can also be partially prevented by checking the HTTP Referer and Origin header from your API. CSRF attacks will have Referer and Origin headers that are unrelated to your application.

The full article can be found here: https://stormpath.com/blog/where-to-store-your-jwts-cookies-vs-html5-web-storage/

They also have a helpful article on how to best design and implement JWTs, with regards to the structure of the token itself: https://stormpath.com/blog/jwt-the-right-way/

How to negate a method reference predicate

Predicate.not( … )

offers a new method Predicate#not

So you can negate the method reference:

Stream<String> s = ...;
long nonEmptyStrings = s.filter(Predicate.not(String::isEmpty)).count();

Getting Python error "from: can't read /var/mail/Bio"

No, it's not the script, it's the fact that your script is not executed by Python at all. If your script is stored in a file named script.py, you have to execute it as python script.py, otherwise the default shell will execute it and it will bail out at the from keyword. (Incidentally, from is the name of a command line utility which prints names of those who have sent mail to the given username, so that's why it tries to access the mailboxes).

Another possibility is to add the following line to the top of the script:

#!/usr/bin/env python

This will instruct your shell to execute the script via python instead of trying to interpret it on its own.

How do I create a crontab through a script

Cron jobs usually are stored in a per-user file under /var/spool/cron

The simplest thing for you to do is probably just create a text file with the job configured, then copy it to the cron spool folder and make sure it has the right permissions (600).

How to tell if node.js is installed or not

Open the command prompt in Windows or terminal in Linux and Mac.Type

node -v

If node is install it will show its version.For eg.,

v6.9.5

Else download it from nodejs.org

How to remove files from git staging area?

Use "git reset HEAD <file>..." to unstage fils

ex : to unstage all files

git reset HEAD .

to unstage one file

git reset HEAD nameFile.txt

Android how to use Environment.getExternalStorageDirectory()

As described in Documentation Environment.getExternalStorageDirectory() :

Environment.getExternalStorageDirectory() Return the primary shared/external storage directory.

This is an example of how to use it reading an image :

String fileName = "stored_image.jpg";
 String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
 String pathDir = baseDir + "/Android/data/com.mypackage.myapplication/";

 File f = new File(pathDir + File.separator + fileName);

        if(f.exists()){
          Log.d("Application", "The file " + file.getName() + " exists!";
         }else{
          Log.d("Application", "The file no longer exists!";
         }

Force drop mysql bypassing foreign key constraint

Drop database exist in all versions of MySQL. But if you want to keep the table structure, here is an idea

mysqldump --no-data --add-drop-database --add-drop-table -hHOSTNAME -uUSERNAME -p > dump.sql

This is a program, not a mysql command

Then, log into mysql and

source dump.sql;

Post values from a multiple select

You need to add a name attribute.

Since this is a multiple select, at the HTTP level, the client just sends multiple name/value pairs with the same name, you can observe this yourself if you use a form with method="GET": someurl?something=1&something=2&something=3.

In the case of PHP, Ruby, and some other library/frameworks out there, you would need to add square braces ([]) at the end of the name. The frameworks will parse that string and wil present it in some easy to use format, like an array.

Apart from manually parsing the request there's no language/framework/library-agnostic way of accessing multiple values, because they all have different APIs

For PHP you can use:

<select name="something[]" id="inscompSelected" multiple="multiple" class="lstSelected">

splitting a string into an array in C++ without using vector

Here's a suggestion: use two indices into the string, say start and end. start points to the first character of the next string to extract, end points to the character after the last one belonging to the next string to extract. start starts at zero, end gets the position of the first char after start. Then you take the string between [start..end) and add that to your array. You keep going until you hit the end of the string.

Automatic exit from Bash shell script on error

Use it in conjunction with pipefail.

set -e
set -o pipefail

-e (errexit): Abort the script at the first error, when a command exits with non-zero status (except in until or while loops, if-tests, and list constructs)

-o pipefail: Causes a pipeline to return the exit status of the last command in the pipe that returned a non-zero return value.

Chapter 33. Options

How To Run PHP From Windows Command Line in WAMPServer

The following solution is specifically for wamp environments:

This foxed me for a little while, tried all the other suggestions, $PATH etc even searched the windows registry looking for clues:

The GUI (wampmanager) indicates I have version 7 selected and yes if I phpinfo() in a page in the browser it will tell me its version 7.x.x yet php -v in the command prompt reports a 5.x.x

If you right click on the wampmanager head to icon->tools->delete unused versions and remove the old version, let it restart the services then the command prompt will return a 7.x.x

This solution means you no longer have the old version if you want to switch between php versions but there is a configuration file in C:\wamp64\wampmanager.conf which appears to specify the version to use with CLI (the parameter is called phpCliVersion). I changed it, restarted the server ... thought I had solved it but no effect perhaps I was a little impatient so I have a feeling there may be some mileage in that.

Hope that helps someone

How to get a table creation script in MySQL Workbench?

Not sure if this is still an issue, but for me in 5.2.35CE it's possible to get the create scripts by:

  1. Database --> Reverse Engineer

  2. Under stored connection, choose your database

  3. Hit "Next" a few times, choose which schema you want to reverse engineer, and let the tool work

  4. You'll get an "EER Diagram" view with all the DB's schema. If you right click on the table you care about and choose "Copy SQL to Clipboard" I think you'll have what you need.

Hopefully this helps someone else that needs it.

Oracle JDBC intermittent Connection Issue

OracleXETNSListener - this service has to be started if it was disabled.

run -> services.msc 

and look out for that services

Class file for com.google.android.gms.internal.zzaja not found

As stated in the Google documentation, Add the latest version of the Google Service plugin (4.0.1 on 06/04/18). Hope this hepls!

buildscript {
    // ...
    dependencies {
        // ...
        classpath 'com.google.gms:google-services:4.0.1' // google-services plugin
    }
}
`

How do I use arrays in cURL POST requests

    $ch = curl_init();

    $data = array(
        'client_id' => 'xx',
        'client_secret' => 'xx',
        'redirect_uri' => $x,
        'grant_type' => 'xxx',
        'code' => $xx,
    );

    $data = http_build_query($data);

    curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
    curl_setopt($ch, CURLOPT_URL, "https://example.com");
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_POST, 1);

    $output = curl_exec($ch);

What is the pythonic way to detect the last element in a 'for' loop?

Use slicing and is to check for the last element:

for data in data_list:
    <code_that_is_done_for_every_element>
    if not data is data_list[-1]:
        <code_that_is_done_between_elements>

Caveat emptor: This only works if all elements in the list are actually different (have different locations in memory). Under the hood, Python may detect equal elements and reuse the same objects for them. For instance, for strings of the same value and common integers.

Install Android App Bundle on device

If you want to install apk from your aab to your device for testing purpose then you need to edit the configuration before running it on the connected device.

  1. Go to Edit Configurations
    enter image description here
  2. Select the Deploy dropdown and change it from "Default apk" to "APK from app bundle".enter image description here
  3. Apply the changes and then run it on the device connected. Build time will increase after making this change.

This will install an apk directly on the device connected from the aab.

How do I perform a JAVA callback between classes?

Use the observer pattern. It works like this:

interface MyListener{
    void somethingHappened();
}

public class MyForm implements MyListener{
    MyClass myClass;
    public MyForm(){
        this.myClass = new MyClass();
        myClass.addListener(this);
    }
    public void somethingHappened(){
       System.out.println("Called me!");
    }
}
public class MyClass{
    private List<MyListener> listeners = new ArrayList<MyListener>();

    public void addListener(MyListener listener) {
        listeners.add(listener);
    }
    void notifySomethingHappened(){
        for(MyListener listener : listeners){
            listener.somethingHappened();
        }
    }
}

You create an interface which has one or more methods to be called when some event happens. Then, any class which needs to be notified when events occur implements this interface.

This allows more flexibility, as the producer is only aware of the listener interface, not a particular implementation of the listener interface.

In my example:

MyClass is the producer here as its notifying a list of listeners.

MyListener is the interface.

MyForm is interested in when somethingHappened, so it is implementing MyListener and registering itself with MyClass. Now MyClass can inform MyForm about events without directly referencing MyForm. This is the strength of the observer pattern, it reduces dependency and increases reusability.

Spring Boot java.lang.NoClassDefFoundError: javax/servlet/Filter

It's not good to change the scope of your application dependencies. Putting the dependency as compile, will provide the dependency also in your artifact that will be installed somewere. The best think to do is configure the RUN configuration of your sping boot application by specifying as stated in documentation :

"Include dependencies with 'Provided' scope" "Enable this option to add dependencies with the Provided scope to the runtime classpath."

enter image description here

Where are shared preferences stored?

Just to save some of you time...

On my Galaxy S v.2.3.3 Shared Preferences are not stored in:/data/data/YOUR_PACKAGE_NAME/shared_prefs/YOUR_PREFS_NAME.xml

but are now located in: /dbdata/databases/YOUR_PACKAGE_NAME/shared_prefs/YOUR_PREFS_NAME.xml

I believe they changed this in 2.3

How to execute python file in linux

I suggest that you add

#!/usr/bin/env python

instead of #!/usr/bin/python at the top of the file. The reason for this is that the python installation may be in different folders in different distros or different computers. By using env you make sure that the system finds python and delegates the script's execution to it.

As said before to make the script executable, something like:

chmod u+x name_of_script.py

should do.

Failed to load the JNI shared Library (JDK)

Downloaded 64 bit JVM from site and installed it manually and updated the system path variable. That solved the issue.

  1. Default JVM is installed in my system was in "C:\Program Files
    (x86)\Java\jre7"
  2. Manually installed JVM got installed in "C:\Program Files\Java\jre7" and after updating this pate to system path variable it worked.