Programs & Examples On #Playstation portable

PlayStation Portable (or PSP) is a portable console device created and developed by Sony.

Ant is using wrong java version

By default the Ant will considered the JRE as the workspace JRE version. You need to change according to your required version by following the below.

In Eclipse:

  • Right click on your build.xml click "Run As", click on "External Tool Configurations..." Select tab JRE.

  • Select the JRE you are using.

  • Re-run the task, it should be fine now.

Assertion failure in dequeueReusableCellWithIdentifier:forIndexPath:

I setup everything correctly in the Storyboard and did a clean build but kept getting the error " must register a nib or a class for the identifier or connect a prototype cell in a storyboard"

[self.tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"Cell"];

Corrected the error but i'm still at a loss. I'm not using a 'custom cell', just a view with a tableview embeded. I have declared the viewcontroller as delegate and datasource and made sure the cell identifier matches in file. whats going on here?

What is an undefined reference/unresolved external symbol error and how do I fix it?

Even though this is a pretty old questions with multiple accepted answers, I'd like to share how to resolve an obscure "undefined reference to" error.

Different versions of libraries

I was using an alias to refer to std::filesystem::path: filesystem is in the standard library since C++17 but my program needed to also compile in C++14 so I decided to use a variable alias:

#if (defined _GLIBCXX_EXPERIMENTAL_FILESYSTEM) //is the included filesystem library experimental? (C++14 and newer: <experimental/filesystem>)
using path_t = std::experimental::filesystem::path;
#elif (defined _GLIBCXX_FILESYSTEM) //not experimental (C++17 and newer: <filesystem>)
using path_t = std::filesystem::path;
#endif

Let's say I have three files: main.cpp, file.h, file.cpp:

  • file.h #include's <experimental::filesystem> and contains the code above
  • file.cpp, the implementation of file.h, #include's "file.h"
  • main.cpp #include's <filesystem> and "file.h"

Note the different libraries used in main.cpp and file.h. Since main.cpp #include'd "file.h" after <filesystem>, the version of filesystem used there was the C++17 one. I used to compile the program with the following commands:

$ g++ -g -std=c++17 -c main.cpp -> compiles main.cpp to main.o
$ g++ -g -std=c++17 -c file.cpp -> compiles file.cpp and file.h to file.o
$ g++ -g -std=c++17 -o executable main.o file.o -lstdc++fs -> links main.o and file.o

This way any function contained in file.o and used in main.o that required path_t gave "undefined reference" errors because main.o referred to std::filesystem::path but file.o to std::experimental::filesystem::path.

Resolution

To fix this I just needed to change <experimental::filesystem> in file.h to <filesystem>.

how to clear localstorage,sessionStorage and cookies in javascript? and then retrieve?

how to completely clear localstorage

localStorage.clear();

how to completely clear sessionstorage

sessionStorage.clear();

[...] Cookies ?

var cookies = document.cookie;

for (var i = 0; i < cookies.split(";").length; ++i)
{
    var myCookie = cookies[i];
    var pos = myCookie.indexOf("=");
    var name = pos > -1 ? myCookie.substr(0, pos) : myCookie;
    document.cookie = name + "=;expires=Thu, 01 Jan 1970 00:00:00 GMT";
}

is there any way to get the value back after clear these ?

No, there isn't. But you shouldn't rely on this if this is related to a security question.

What is the current directory in a batch file?

It usually is the directory from which the batch file is started, but if you start the batch file from a shortcut, a different starting directory could be given. Also, when you'r in cmd, and your current directory is c:\dir3, you can still start the batch file using c:\dir1\dir2\batch.bat in which case, the current directory will be c:\dir3.

Change border color on <select> HTML form

No, the <select> control is a system-level control, not a client-level control in IE. A few versions back it didn't even play nicely-with z-index, putting itself on top of virtually everything.

To do anything fancy you'll have to emulate the functionality using CSS and your own elements.

How to embed PDF file with responsive width

Simply do this:

<object data="resume.pdf" type="application/pdf" width="100%" height="800px"> 
  <p>It appears you don't have a PDF plugin for this browser.
   No biggie... you can <a href="resume.pdf">click here to
  download the PDF file.</a></p>  
</object>

Adding Jar files to IntellijIdea classpath

On the Mac version I was getting the error when trying to run JSON-Clojure.json.clj, which is the script to export a database table to JSON. To get it to work I had to download the latest Clojure JAR from http://clojure.org/ and then right-click on PHPStorm app in the Finder and "Show Package Contents". Then go to Contents in there. Then open the lib folder, and see a bunch of .jar files. Copy the clojure-1.8.0.jar file from the unzipped archive I downloaded from clojure.org into the aforementioned lib folder inside the PHPStorm.app/Contents/lib. Restart the app. Now it freaking works.

EDIT: You also have to put the JSR-223 script engine into PHPStorm.app/Contents/lib. It can be built from https://github.com/ato/clojure-jsr223 or downloaded from https://www.dropbox.com/s/jg7s0c41t5ceu7o/clojure-jsr223-1.5.1.jar?dl=0 .

How to 'foreach' a column in a DataTable using C#?

int countRow = dt.Rows.Count;
int countCol = dt.Columns.Count;

for (int iCol = 0; iCol < countCol; iCol++)
{
     DataColumn col = dt.Columns[iCol];

     for (int iRow = 0; iRow < countRow; iRow++)
     {
         object cell = dt.Rows[iRow].ItemArray[iCol];

     }
}

Add another class to a div

In the DOM, the class of an element is just each class separated by a space. You would just need to implement the parsing logic to insert / remove the classes as necesary.

I wonder though... why wouldn't you want to use jQuery? It makes this kind of problem trivially easy.

How to set default value for column of new created table from select statement in 11g

The reason is that CTAS (Create table as select) does not copy any metadata from the source to the target table, namely

  • no primary key
  • no foreign keys
  • no grants
  • no indexes
  • ...

To achieve what you want, I'd either

  • use dbms_metadata.get_ddl to get the complete table structure, replace the table name with the new name, execute this statement, and do an INSERT afterward to copy the data
  • or keep using CTAS, extract the not null constraints for the source table from user_constraints and add them to the target table afterwards

'too many values to unpack', iterating over a dict. key=>string, value=>list

In Python3 iteritems() is no longer supported

Use .items

for field, possible_values in fields.items():
    print(field, possible_values)

What does 'index 0 is out of bounds for axis 0 with size 0' mean?

Essentially it means you don't have the index you are trying to reference. For example:

df = pd.DataFrame()
df['this']=np.nan
df['my']=np.nan
df['data']=np.nan
df['data'][0]=5 #I haven't yet assigned how long df[data] should be!
print(df)

will give me the error you are referring to, because I haven't told Pandas how long my dataframe is. Whereas if I do the exact same code but I DO assign an index length, I don't get an error:

df = pd.DataFrame(index=[0,1,2,3,4])
df['this']=np.nan
df['is']=np.nan
df['my']=np.nan
df['data']=np.nan
df['data'][0]=5 #since I've properly labelled my index, I don't run into this problem!
print(df)

Hope that answers your question!

Fill remaining vertical space with CSS using display:flex

Here is the codepen demo showing the solution:

Important highlights:

  • all containers from html, body, ... .container, should have the height set to 100%
  • introducing flex to ANY of the flex items will trigger calculation of the items sizes based on flex distribution:
    • if only one cell is set to flex, for example: flex: 1 then this flex item will occupy the remaining of the space
    • if there are more than one with the flex property, the calculation will be more complicated. For example, if the item 1 is set to flex: 1 and the item 2 is se to flex: 2 then the item 2 will take twice more of the remaining space
  • Main Size Property

What are the differences between a superkey and a candidate key?

One candidate key is chosen as the primary key. Other candidate keys are called alternate keys.

Finding the length of an integer in C

Kindly find my answer it is in one line code:

#include <stdio.h> int main(void){ int c = 12388884; printf("length of integer is: %d",printf("%d",c)); return 0; }

that is simple and smart! Upvote if you like this!

Bash: Echoing a echo command with a variable in bash

You just need to use single quotes:

$ echo "$TEST"
test
$ echo '$TEST'
$TEST

Inside single quotes special characters are not special any more, they are just normal characters.

What is the best method to merge two PHP objects?

I would go with linking the second object into a property of the first object. If the second object is the result of a function or method, use references. Ex:

//Not the result of a method
$obj1->extra = new Class2();

//The result of a method, for instance a factory class
$obj1->extra =& Factory::getInstance('Class2');

Set a path variable with spaces in the path in a Windows .cmd file or batch file

The proper way to do this is like so:

@ECHO off
SET MY_PATH=M:\Dir\^
With Spaces\Sub Folder^
\Dir\Folder
:: calls M:\Dir\With Spaces\Sub Folder\Dir\Folder\hello.bat
CALL "%MY_PATH%\hello.bat"
pause

How to replace local branch with remote branch entirely in Git?

  1. Make sure you've checked out the branch you're replacing (from Zoltán's comment).
  2. Assuming that master is the local branch you're replacing, and that "origin/master" is the remote branch you want to reset to:

    git reset --hard origin/master
    

This updates your local HEAD branch to be the same revision as origin/master, and --hard will sync this change into the index and workspace as well.

Need to remove href values when printing in Chrome

If you use the following CSS

<link href="~/Content/common/bootstrap.css" rel="stylesheet" type="text/css"    />
<link href="~/Content/common/bootstrap.min.css" rel="stylesheet" type="text/css" />
<link href="~/Content/common/site.css" rel="stylesheet" type="text/css" />

just change it into the following style by adding media="screen"

<link href="~/Content/common/bootstrap.css" rel="stylesheet" **media="screen"** type="text/css" />
<link href="~/Content/common/bootstrap.min.css" rel="stylesheet" **media="screen"** type="text/css" />
<link href="~/Content/common/site.css" rel="stylesheet" **media="screen"** type="text/css" />

I think it will work.

the former answers like

    @media print {
  a[href]:after {
    content: none !important;
  }
}

were not worked well in the chrome browse.

System.web.mvc missing

Easiest way to solve this problem is install ASP.NET MVC 3 from Web Platforms installer.

enter image description here

http://www.microsoft.com/web/downloads/

Or by using Nuget command

Install-Package Microsoft.AspNet.Mvc -Version 3.0.50813.1

Should composer.lock be committed to version control?

For applications/projects: Definitely yes.

The composer documentation states on this (with emphasis):

Commit your application's composer.lock (along with composer.json) into version control.

Like @meza said: You should commit the lock file so you and your collaborators are working on the same set of versions and prevent you from sayings like "But it worked on my computer". ;-)

For libraries: Probably not.

The composer documentation notes on this matter:

Note: For libraries it is not necessarily recommended to commit the lock file (...)

And states here:

For your library you may commit the composer.lock file if you want to. This can help your team to always test against the same dependency versions. However, this lock file will not have any effect on other projects that depend on it. It only has an effect on the main project.

For libraries I agree with @Josh Johnson's answer.

Loading existing .html file with android WebView

Copy and Paste Your .html file in the assets folder of your Project and add below code in your Activity on onCreate().

        WebView view = new WebView(this);
        view.getSettings().setJavaScriptEnabled(true);
        view.loadUrl("file:///android_asset/**YOUR FILE NAME**.html");
        view.setBackgroundColor(Color.TRANSPARENT);
        setContentView(view);

CSS to prevent child element from inheriting parent styles

CSS rules are inherited by default - hence the "cascading" name. To get what you want you need to use !important:

form div
{
    font-size: 12px;
    font-weight: bold;
}

div.content
{
    // any rule you want here, followed by !important
}

Generate a unique id

Why not just use ToString?

public string generateID()
{
    return Guid.NewGuid().ToString("N");
}

If you would like it to be based on a URL, you could simply do the following:

public string generateID(string sourceUrl)
{
    return string.Format("{0}_{1:N}", sourceUrl, Guid.NewGuid());
}

If you want to hide the URL, you could use some form of SHA1 on the sourceURL, but I'm not sure what that might achieve.

How can I move a tag on a git branch to a different commit?

One other way:

Move tag in remote repo.(Replace HEAD with any other if needed.)

$ git push --force origin HEAD:refs/tags/v0.0.1.2

Fetch changes back.

$ git fetch --tags

How do I see all foreign keys to a table or column?

For a Table:

SELECT 
  TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME
FROM
  INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE
  REFERENCED_TABLE_SCHEMA = '<database>' AND
  REFERENCED_TABLE_NAME = '<table>';

For a Column:

SELECT 
  TABLE_NAME,COLUMN_NAME,CONSTRAINT_NAME, REFERENCED_TABLE_NAME,REFERENCED_COLUMN_NAME
FROM
  INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE
  REFERENCED_TABLE_SCHEMA = '<database>' AND
  REFERENCED_TABLE_NAME = '<table>' AND
  REFERENCED_COLUMN_NAME = '<column>';

Basically, we changed REFERENCED_TABLE_NAME with REFERENCED_COLUMN_NAME in the where clause.

Java compile error: "reached end of file while parsing }"

You have to open and close your class with { ... } like:

public class mod_MyMod extends BaseMod
{
  public String Version()
  {
    return "1.2_02";
  }

  public void AddRecipes(CraftingManager recipes)
  {
     recipes.addRecipe(new ItemStack(Item.diamond), new Object[] {
        "#", Character.valueOf('#'), Block.dirt });
  }
}

Python IndentationError unindent does not match any outer indentation level

You are mixing tabs and spaces. Don't do that. Specifically, the __init__ function body is indented with tabs while your on_data method is not.

Here is a screenshot of your code in my text editor; I set the tab stop to 8 spaces (which is what Python uses) and selected the text, which causes the editor to display tabs with continuous horizontal lines:

highlighted code with tabs shown as lines

You have your editor set to expanding tabs to every fourth column instead, so the methods appear to line up.

Run your code with:

python -tt scriptname.py

and fix all errors that finds. Then configure your editor to use spaces only for indentation; a good editor will insert 4 spaces every time you use the TAB key.

no suitable HttpMessageConverter found for response type

A refinement of Vadim Zin4uk's answer is just to use the existing GsonHttpMessageConverter class but invoke the setSupportedMediaTypes() setter.

For spring boot apps, this results into adding to following to your configuration classes:

@Bean
public GsonHttpMessageConverter gsonHttpMessageConverter(Gson gson) {
    GsonHttpMessageConverter converter = new GsonHttpMessageConverter();
    converter.setGson(gson);
    List<MediaType> supportedMediaTypes = converter.getSupportedMediaTypes();
    if (! supportedMediaTypes.contains(TEXT_PLAIN)) {
        supportedMediaTypes = new ArrayList<>(supportedMediaTypes);
        supportedMediaTypes.add(TEXT_PLAIN);
        converter.setSupportedMediaTypes(supportedMediaTypes);
    }
    return converter;
}

What is default color for text in textview?

I found that android:textColor="@android:color/secondary_text_dark" provides a closer result to the default TextView color than android:textColor="@android:color/tab_indicator_text". I suppose you have to switch between secondary_text_dark/light depending on the Theme you are using

SQL Server: Attach incorrect version 661

SQL Server 2008 databases are version 655. SQL Server 2008 R2 databases are 661. You are trying to attach an 2008 R2 database (v. 661) to an 2008 instance and this is not supported. Once the database has been upgraded to an 2008 R2 version, it cannot be downgraded. You'll have to either upgrade your 2008 SP2 instance to R2, or you have to copy out the data in that database into an 2008 database (eg using the data migration wizard, or something equivalent).

The message is misleading, to say the least, it says 662 because SQL Server 2008 SP2 does support 662 as a database version, this is when 15000 partitions are enabled in the database, see Support for 15000 Partitions.docx. Enabling the support bumps the DB version to 662, disabling it moves it back to 655. But SQL Server 2008 SP2 does not support 661 (the R2 version).

What does the "__block" keyword mean?

@bbum covers blocks in depth in a blog post and touches on the __block storage type.

__block is a distinct storage type

Just like static, auto, and volatile, __block is a storage type. It tells the compiler that the variable’s storage is to be managed differently.

...

However, for __block variables, the block does not retain. It is up to you to retain and release, as needed.
...

As for use cases you will find __block is sometimes used to avoid retain cycles since it does not retain the argument. A common example is using self.

//Now using myself inside a block will not 
//retain the value therefore breaking a
//possible retain cycle.
__block id myself = self;

How can I add a hint text to WPF textbox?

You can accomplish this much more easily with a VisualBrush and some triggers in a Style:

<TextBox>
    <TextBox.Style>
        <Style TargetType="TextBox" xmlns:sys="clr-namespace:System;assembly=mscorlib">
            <Style.Resources>
                <VisualBrush x:Key="CueBannerBrush" AlignmentX="Left" AlignmentY="Center" Stretch="None">
                    <VisualBrush.Visual>
                        <Label Content="Search" Foreground="LightGray" />
                    </VisualBrush.Visual>
                </VisualBrush>
            </Style.Resources>
            <Style.Triggers>
                <Trigger Property="Text" Value="{x:Static sys:String.Empty}">
                    <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                </Trigger>
                <Trigger Property="Text" Value="{x:Null}">
                    <Setter Property="Background" Value="{StaticResource CueBannerBrush}" />
                </Trigger>
                <Trigger Property="IsKeyboardFocused" Value="True">
                    <Setter Property="Background" Value="White" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </TextBox.Style>
</TextBox>

To increase the re-usability of this Style, you can also create a set of attached properties to control the actual cue banner text, color, orientation etc.

Predicate Delegates in C#

A delegate defines a reference type that can be used to encapsulate a method with a specific signature. C# delegate Life cycle: The life cycle of C# delegate is

  • Declaration
  • Instantiation
  • INVACATION

learn more form http://asp-net-by-parijat.blogspot.in/2015/08/what-is-delegates-in-c-how-to-declare.html

How to get the clicked link's href with jquery?

$(".testClick").click(function () {
         var value = $(this).attr("href");
         alert(value );     
}); 

When you use $(".className") you are getting the set of all elements that have that class. Then when you call attr it simply returns the value of the first item in the collection.

How to fix Error: laravel.log could not be opened?

Maximum people's are suggesting to change file permission 777 or 775, which I believe not an appropriate approach to solve this problem. You just need to change the ownership of storage and bootstrap folder.

In below Image you can see all my files/folder are under the root user(except storage and bootstrap, because I changed the ownership ),but I logged in as a administrator(before changing ownership) that's why it always giving permission denied. So I need to change the ownership of this two folder to administrator

So how I did this, go to your project directory and run below commands. sudo chown -R yourusername:www-data storage, sudo chmod -R ug+w storage, sudo chown -R yourusername:www-data bootstrap, sudo chmod -R ug+w bootstrap

Unable to resolve "unable to get local issuer certificate" using git on Windows with self-signed certificate

I have tried all approach mentioned here but no luck with any. Finally i found a different approach what i did is

  • Generated ssh public /private key on my system for git repo

  • copy ssh key to your git account and use ssh instead of https in git clone .check below step to generate ssh key

Open Git Bash.

Paste the text below, substituting in your GitHub email address.

$ ssh-keygen -t rsa -b 4096 -C "[email protected]"

This creates a new ssh key, using the provided email as a label.

Generating public/private rsa key pair. When you're prompted to "Enter a file in which to save the key," press Enter. This accepts the default file location.

Enter a file in which to save the key (/c/Users/you/.ssh/id_rsa):[Press enter]

open resource with relative path in Java

In Order to obtain real path to the file you can try this:

URL fileUrl = Resourceloader.class.getResource("resources/repository/SSL-Key/cert.jks");
String pathToClass = fileUrl.getPath;    

Resourceloader is classname here. "resources/repository/SSL-Key/cert.jks" is relative path to the file. If you had your guiclass in ./package1/java with rest of folder structure remaining, you would take "../resources/repository/SSL-Key/cert.jks" as relative path because of rules defining relative path.

This way you can read your file with BufferedReader. DO NOT USE THE STRING to identify the path to the file, because if you have spaces or some characters from not english alphabet in your path, you will get problems and the file will not be found.

BufferedReader bufferedReader = new BufferedReader(
                        new InputStreamReader(fileUrl.openStream()));

Offset a background image from the right using CSS

If you have a fixed width element and know the width of your background image, you can simply set the background-position to : the element's width - the image's width - the gap you want on the right.

For example : with a 100px-wide element and a 300px-wide image, to get a gap of 10px on the right, you set it to 100-300-10=-210px :

#myElement {
  background:url(my_image.jpg) no-repeat -210px top;
  width:100px;
}

And you get the rightmost 80 pixels of your image on the left of your element, and a gap of 20px on the right.

I know it can sound stupid but sometimes it saves the time... I use that much in a vertical manner (gap at bottom) for navigation links with text below image.

Not sure it applies to your case though.

Total Number of Row Resultset getRow Method

The getRow() method retrieves the current row number, not the number of rows. So before starting to iterate over the ResultSet, getRow() returns 0.

To get the actual number of rows returned after executing your query, there is no free method: you are supposed to iterate over it.

Yet, if you really need to retrieve the total number of rows before processing them, you can:

  1. ResultSet.last()
  2. ResultSet.getRow() to get the total number of rows
  3. ResultSet.beforeFirst()
  4. Process the ResultSet normally

How to complete the RUNAS command in one line

The runas command does not allow a password on its command line. This is by design (and also the reason you cannot pipe a password to it as input). Raymond Chen says it nicely:

The RunAs program demands that you type the password manually. Why doesn't it accept a password on the command line?

This was a conscious decision. If it were possible to pass the password on the command line, people would start embedding passwords into batch files and logon scripts, which is laughably insecure.

In other words, the feature is missing to remove the temptation to use the feature insecurely.

How can I use the MS JDBC driver with MS SQL Server 2008 Express?

If your databaseName value is correct, then use this: DriverManger.getconnection("jdbc:sqlserver://ServerIp:1433;user=myuser;password=mypassword;databaseName=databaseName;")

Force LF eol in git repo and working copy

To force LF line endings for all text files, you can create .gitattributes file in top-level of your repository with the following lines (change as desired):

# Ensure all C and PHP files use LF.
*.c         eol=lf
*.php       eol=lf

which ensures that all files that Git considers to be text files have normalized (LF) line endings in the repository (normally core.eol configuration controls which one do you have by default).

Based on the new attribute settings, any text files containing CRLFs should be normalized by Git. If this won't happen automatically, you can refresh a repository manually after changing line endings, so you can re-scan and commit the working directory by the following steps (given clean working directory):

$ echo "* text=auto" >> .gitattributes
$ rm .git/index     # Remove the index to force Git to
$ git reset         # re-scan the working directory
$ git status        # Show files that will be normalized
$ git add -u
$ git add .gitattributes
$ git commit -m "Introduce end-of-line normalization"

or as per GitHub docs:

git add . -u
git commit -m "Saving files before refreshing line endings"
git rm --cached -r . # Remove every file from Git's index.
git reset --hard # Rewrite the Git index to pick up all the new line endings.
git add . # Add all your changed files back, and prepare them for a commit.
git commit -m "Normalize all the line endings" # Commit the changes to your repository.

See also: @Charles Bailey post.

In addition, if you would like to exclude any files to not being treated as a text, unset their text attribute, e.g.

manual.pdf      -text

Or mark it explicitly as binary:

# Denote all files that are truly binary and should not be modified.
*.png binary
*.jpg binary

To see some more advanced git normalization file, check .gitattributes at Drupal core:

# Drupal git normalization
# @see https://www.kernel.org/pub/software/scm/git/docs/gitattributes.html
# @see https://www.drupal.org/node/1542048

# Normally these settings would be done with macro attributes for improved
# readability and easier maintenance. However macros can only be defined at the
# repository root directory. Drupal avoids making any assumptions about where it
# is installed.

# Define text file attributes.
# - Treat them as text.
# - Ensure no CRLF line-endings, neither on checkout nor on checkin.
# - Detect whitespace errors.
#   - Exposed by default in `git diff --color` on the CLI.
#   - Validate with `git diff --check`.
#   - Deny applying with `git apply --whitespace=error-all`.
#   - Fix automatically with `git apply --whitespace=fix`.

*.config  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.css     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.dist    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.engine  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.html    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=html
*.inc     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.install text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.js      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.json    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.lock    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.map     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.md      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.module  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.php     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.po      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.profile text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.script  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.sh      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.sql     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.svg     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.theme   text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.twig    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.txt     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.xml     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.yml     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2

# Define binary file attributes.
# - Do not treat them as text.
# - Include binary diff in patches instead of "binary files differ."
*.eot     -text diff
*.exe     -text diff
*.gif     -text diff
*.gz      -text diff
*.ico     -text diff
*.jpeg    -text diff
*.jpg     -text diff
*.otf     -text diff
*.phar    -text diff
*.png     -text diff
*.svgz    -text diff
*.ttf     -text diff
*.woff    -text diff
*.woff2   -text diff

See also:

JQuery datepicker language

Include js files of datepicker and language (locales)

'resource/bower_components/bootstrap-datepicker/dist/js/bootstrap-datepicker.min.js',
'resource/bower_components/bootstrap-datepicker/dist/locales/bootstrap-datepicker.sv.min.js',

In the options of the datepicker, set the language as below:

$('.datepicker').datepicker({'language' : 'sv'});

How to make child element higher z-index than parent?

Try using this code, it worked for me:

z-index: unset;

SQL Connection Error: System.Data.SqlClient.SqlException (0x80131904)

See my post here

How are you? I had the same problem while i was trying connect to MSSQL Server remotely using jdbc (dbeaver on debian).

After a while, i found out that my firewall configuration was not correctly. So maybe it could help you!

Configure the firewall to allow network traffic that is related to SQL Server and to the SQL Server Browser service.

Four exceptions must be configured in Windows Firewall to allow access to SQL Server:

A port exception for TCP Port 1433. In the New Inbound Rule Wizard dialog, use the following information to create a port exception: Select Port Select TCP and specify port 1433 Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule “SQL – TCP 1433" A port exception for UDP Port 1434. Click New Rule again and use the following information to create another port exception: Select Port Select UDP and specify port 1434 Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule “SQL – UDP 1434 A program exception for sqlservr.exe. Click New Rule again and use the following information to create a program exception: Select Program Click Browse to select ‘sqlservr.exe’ at this location: [C:\Program Files\Microsoft SQL Server\MSSQL11.\MSSQL\Binn\sqlservr.exe] where is the name of your SQL instance. Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule SQL – sqlservr.exe A program exception for sqlbrowser.exe Click New Rule again and use the following information to create another program exception: Select Program Click Browse to select sqlbrowser.exe at this location: [C:\Program Files\Microsoft SQL Server\90\Shared\sqlbrowser.exe]. Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule SQL - sqlbrowser.exe

Source: http://blog.citrix24.com/configure-sql-express-to-accept-remote-connections/

c# open a new form then close the current form?

You weren't specific, but it looks like you were trying to do what I do in my Win Forms apps: start with a Login form, then after successful login, close that form and put focus on a Main form. Here's how I do it:

  1. make frmMain the startup form; this is what my Program.cs looks like:

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new frmMain());
    }
    
  2. in my frmLogin, create a public property that gets initialized to false and set to true only if a successful login occurs:

    public bool IsLoggedIn { get; set; }
    
  3. my frmMain looks like this:

    private void frmMain_Load(object sender, EventArgs e)
    {
        frmLogin frm = new frmLogin();
        frm.IsLoggedIn = false;
        frm.ShowDialog();
    
        if (!frm.IsLoggedIn)
        {
            this.Close();
            Application.Exit();
            return;
        }
    

No successful login? Exit the application. Otherwise, carry on with frmMain. Since it's the startup form, when it closes, the application ends.

DELETE_FAILED_INTERNAL_ERROR Error while Installing APK

I also had the same problem, I tried the solution to disable the instant run, but you can not use the instant run, which for me is harmful, because it is an extremely useful tool.

I found another solution, which is to delete the "build" folder and re-run the project, and the error disappears, the app is executed and I can use the instant run.

Delete this folder

Is there a label/goto in Python?

To answer the @ascobol's question using @bobince's suggestion from the comments:

for i in range(5000):
    for j in range(3000):
        if should_terminate_the_loop:
           break
    else: 
        continue # no break encountered
    break

The indent for the else block is correct. The code uses obscure else after a loop Python syntax. See Why does python use 'else' after for and while loops?

Center the content inside a column in Bootstrap 4

_x000D_
_x000D_
<div class="container">_x000D_
    <div class="row">_x000D_
        <div class="col d-flex justify-content-center">_x000D_
             CenterContent_x000D_
        </div>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Enable 'flex' for the column as we want & use justify-content-center

SQL Server reports 'Invalid column name', but the column is present and the query works through management studio

I eventually shut-down and restarted Microsoft SQL Server Management Studio; and that fixed it for me. But at other times, just starting a new query window was enough.

MySQL - Rows to Columns

SELECT 
    hostid, 
    sum( if( itemname = 'A', itemvalue, 0 ) ) AS A,  
    sum( if( itemname = 'B', itemvalue, 0 ) ) AS B, 
    sum( if( itemname = 'C', itemvalue, 0 ) ) AS C 
FROM 
    bob 
GROUP BY 
    hostid;

Best practice for using assert?

The English language word assert here is used in the sense of swear, affirm, avow. It doesn't mean "check" or "should be". It means that you as a coder are making a sworn statement here:

# I solemnly swear that here I will tell the truth, the whole truth, 
# and nothing but the truth, under pains and penalties of perjury, so help me FSM
assert answer == 42

If the code is correct, barring Single-event upsets, hardware failures and such, no assert will ever fail. That is why the behaviour of the program to an end user must not be affected. Especially, an assert cannot fail even under exceptional programmatic conditions. It just doesn't ever happen. If it happens, the programmer should be zapped for it.

Perl - If string contains text?

If you just need to search for one string within another, use the index function (or rindex if you want to start scanning from the end of the string):

if (index($string, $substring) != -1) {
   print "'$string' contains '$substring'\n";
}

To search a string for a pattern match, use the match operator m//:

if ($string =~ m/pattern/) {
    print "'$string' matches the pattern\n";       
}

How to pass a URI to an intent?

you can do like this. imageuri can be converted into string like this.

intent.putExtra("imageUri", imageUri.toString());

Format in kotlin string templates

Since String.format is only an extension function (see here) which internally calls java.lang.String.format you could write your own extension function using Java's DecimalFormat if you need more flexibility:

fun Double.format(fracDigits: Int): String {
    val df = DecimalFormat()
    df.setMaximumFractionDigits(fracDigits)
    return df.format(this)
}

println(3.14159.format(2)) // 3.14

How can I truncate a double to only two decimal places in Java?

If you want that for display purposes, use java.text.DecimalFormat:

 new DecimalFormat("#.##").format(dblVar);

If you need it for calculations, use java.lang.Math:

 Math.floor(value * 100) / 100;

Convert ArrayList<String> to String[] array

Use like this.

List<String> stockList = new ArrayList<String>();
stockList.add("stock1");
stockList.add("stock2");

String[] stockArr = new String[stockList.size()];
stockArr = stockList.toArray(stockArr);

for(String s : stockArr)
    System.out.println(s);

Unable to load DLL (Module could not be found HRESULT: 0x8007007E)

Ensure that all dependencies of your own dll are present near the dll, or in System32.

SUM OVER PARTITION BY

remove partition by and add group by clause,

SELECT BrandId
      ,SUM(ICount) totalSum
  FROM Table 
WHERE DateId  = 20130618
GROUP BY BrandId

HTML image bottom alignment inside DIV container

<div> with some proportions

div {
  position: relative;
  width: 100%;
  height: 100%;
}

<img>'s with their own proportions

img {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  width: auto; /* to keep proportions */
  height: auto; /* to keep proportions */
  max-width: 100%; /* not to stand out from div */
  max-height: 100%; /* not to stand out from div */
  margin: auto auto 0; /* position to bottom and center */
}

Do I need to pass the full path of a file in another directory to open()?

You have to specify the path that you are working on:

source = '/home/test/py_test/'
for root, dirs, filenames in os.walk(source):
    for f in filenames:
        print f
        fullpath = os.path.join(source, f)
        log = open(fullpath, 'r')

How to simulate key presses or a click with JavaScript?

Or even shorter, with only standard modern Javascript:

var first_link = document.getElementsByTagName('a')[0];
first_link.dispatchEvent(new MouseEvent('click'));

The new MouseEvent constructor takes a required event type name, then an optional object (at least in Chrome). So you could, for example, set some properties of the event:

first_link.dispatchEvent(new MouseEvent('click', {bubbles: true, cancelable: true}));

Convert hex color value ( #ffffff ) to integer value

The real answer is this simplest and easiest ....

String white = "#ffffff";
int whiteInt = Color.parseColor(white);

What is the JavaScript equivalent of var_dump or print_r in PHP?

I put this forward to help anyone needing something readily practical for giving you a nice, prettified (indented) picture of a JS Node. None of the other solutions worked for me for a Node ("cyclical error" or whatever...). This walks you through the tree under the DOM Node (without using recursion) and gives you the depth, tagName (if applicable) and textContent (if applicable).

Any other details from the nodes you encounter as you walk the tree under the head node can be added as per your interest...

function printRNode( node ){
    // make sort of human-readable picture of the node... a bit like PHP print_r

    if( node === undefined || node === null ){
        throwError( 'node was ' + typeof node );
    }
    let s = '';

    // NB walkDOM could be made into a utility function which you could 
    // call with one or more callback functions as parameters...

    function walkDOM( headNode ){
      const stack = [ headNode ];
      const depthCountDowns = [ 1 ];
      while (stack.length > 0) {
        const node = stack.pop();
        const depth = depthCountDowns.length - 1;
        // TODO non-text, non-BR nodes could show more details (attributes, properties, etc.)
        const stringRep = node.nodeType === 3? 'TEXT: |' + node.nodeValue + '|' : 'tag: ' + node.tagName;
        s += '  '.repeat( depth ) + stringRep + '\n';
        const lastIndex = depthCountDowns.length - 1;
        depthCountDowns[ lastIndex ] = depthCountDowns[ lastIndex ] - 1;
        if( node.childNodes.length ){
            depthCountDowns.push( node.childNodes.length );
            stack.push( ... Array.from( node.childNodes ).reverse() );
        }
        while( depthCountDowns[ depthCountDowns.length - 1 ] === 0 ){
            depthCountDowns.splice( -1 );
        }
      }
    } 
    walkDOM( node );
    return s;
}

How to print the value of a Tensor object in TensorFlow?

Enable the eager execution which is introduced in tensorflow after version 1.10. It's very easy to use.

# Initialize session
import tensorflow as tf
tf.enable_eager_execution()


# Some tensor we want to print the value of
a = tf.constant([1.0, 3.0])

print(a)

CharSequence VS String in Java?

I believe it is best to use CharSequence. The reason is that String implements CharSequence, therefore you can pass a String into a CharSequence, HOWEVER you cannot pass a CharSequence into a String, as CharSequence doesn't not implement String. ALSO, in Android the EditText.getText() method returns an Editable, which also implements CharSequence and can be passed easily into one, while not easily into a String. CharSequence handles all!

Display the current date and time using HTML and Javascript with scrollable effects in hta application

<div id="clockbox" style="font:14pt Arial; color:#FF0000;text-align: center; border:1px solid red;background:cyan; height:50px;padding-top:12px;"></div>

Items in JSON object are out of order using "json.dumps"?

As others have mentioned the underlying dict is unordered. However there are OrderedDict objects in python. ( They're built in in recent pythons, or you can use this: http://code.activestate.com/recipes/576693/ ).

I believe that newer pythons json implementations correctly handle the built in OrderedDicts, but I'm not sure (and I don't have easy access to test).

Old pythons simplejson implementations dont handle the OrderedDict objects nicely .. and convert them to regular dicts before outputting them.. but you can overcome this by doing the following:

class OrderedJsonEncoder( simplejson.JSONEncoder ):
   def encode(self,o):
      if isinstance(o,OrderedDict.OrderedDict):
         return "{" + ",".join( [ self.encode(k)+":"+self.encode(v) for (k,v) in o.iteritems() ] ) + "}"
      else:
         return simplejson.JSONEncoder.encode(self, o)

now using this we get:

>>> import OrderedDict
>>> unordered={"id":123,"name":"a_name","timezone":"tz"}
>>> ordered = OrderedDict.OrderedDict( [("id",123), ("name","a_name"), ("timezone","tz")] )
>>> e = OrderedJsonEncoder()
>>> print e.encode( unordered )
{"timezone": "tz", "id": 123, "name": "a_name"}
>>> print e.encode( ordered )
{"id":123,"name":"a_name","timezone":"tz"}

Which is pretty much as desired.

Another alternative would be to specialise the encoder to directly use your row class, and then you'd not need any intermediate dict or UnorderedDict.

How does an SSL certificate chain bundle work?

You need to use the openssl pkcs12 -export -chain -in server.crt -CAfile ...

See https://www.openssl.org/docs/apps/pkcs12.html

How to sort a Pandas DataFrame by index?

Slightly more compact:

df = pd.DataFrame([1, 2, 3, 4, 5], index=[100, 29, 234, 1, 150], columns=['A'])
df = df.sort_index()
print(df)

Note:

Byte Array to Hex String

Consider the hex() method of the bytes type on Python 3.5 and up:

>>> array_alpha = [ 133, 53, 234, 241 ]
>>> print(bytes(array_alpha).hex())
8535eaf1

EDIT: it's also much faster than hexlify (modified @falsetru's benchmarks above)

from timeit import timeit
N = 10000
print("bytearray + hexlify ->", timeit(
    'binascii.hexlify(data).decode("ascii")',
    setup='import binascii; data = bytearray(range(255))',
    number=N,
))
print("byte + hex          ->", timeit(
    'data.hex()',
    setup='data = bytes(range(255))',
    number=N,
))

Result:

bytearray + hexlify -> 0.011218150997592602
byte + hex          -> 0.005952142993919551

VB6 IDE cannot load MSCOMCTL.OCX after update KB 2687323

To Fix the Problem:

Make a Batch file with the following code:

@echo off
reg query "HKEY_CLASSES_ROOT\typelib\{831FDD16-0C5C-11D2-A9FC-0000F8754DA1}\2.1"
if %errorlevel%==0 GOTO DELREGKEY
if %errorlevel%==1 GOTO REGISTEROCX

:DELREGKEY
reg delete hkcr\typelib\{831FDD16-0C5C-11D2-A9FC-0000F8754DA1}\2.0 /f

:REGISTEROCX
if exist %systemroot%\SysWOW64\cscript.exe goto 64 
%systemroot%\system32\regsvr32 /u mscomctl.ocx /s
%systemroot%\system32\regsvr32 mscomctl.ocx /s
exit

:64 
%systemroot%\sysWOW64\regsvr32 /u mscomctl.ocx /s
%systemroot%\sysWOW64\regsvr32 mscomctl.ocx /s
exit

Map a 2D array onto a 1D array

The typical formula for recalculation of 2D array indices into 1D array index is

index = indexX * arrayWidth + indexY;

Alternatively you can use

index = indexY * arrayHeight + indexX;

(assuming that arrayWidth is measured along X axis, and arrayHeight along Y axis)

Of course, one can come up with many different formulae that provide alternative unique mappings, but normally there's no need to.

In C/C++ languages built-in multidimensional arrays are stored in memory so that the last index changes the fastest, meaning that for an array declared as

int xy[10][10];

element xy[5][3] is immediately followed by xy[5][4] in memory. You might want to follow that convention as well, choosing one of the above two formulae depending on which index (X or Y) you consider to be the "last" of the two.

Is it possible to reference one CSS rule within another?

Just add the classes to your html

<div class="someDiv radius opacity"></div>

How do I get the web page contents from a WebView?

You also need to annotate the method with @JavascriptInterface if your targetSdkVersion is >= 17 - because there is new security requirements in SDK 17, i.e. all javascript methods must be annotated with @JavascriptInterface. Otherwise you will see error like: Uncaught TypeError: Object [object Object] has no method 'processHTML' at null:1

List files in local git repo?

git ls-tree --full-tree -r HEAD and git ls-files return all files at once. For a large project with hundreds or thousands of files, and if you are interested in a particular file/directory, you may find more convenient to explore specific directories. You can do it by obtaining the ID/SHA-1 of the directory that you want to explore and then use git cat-file -p [ID/SHA-1 of directory]. For example:

git cat-file -p 14032aabd85b43a058cfc7025dd4fa9dd325ea97
100644 blob b93a4953fff68df523aa7656497ee339d6026d64    glyphicons-halflings-regular.eot
100644 blob 94fb5490a2ed10b2c69a4a567a4fd2e4f706d841    glyphicons-halflings-regular.svg
100644 blob 1413fc609ab6f21774de0cb7e01360095584f65b    glyphicons-halflings-regular.ttf
100644 blob 9e612858f802245ddcbf59788a0db942224bab35    glyphicons-halflings-regular.woff
100644 blob 64539b54c3751a6d9adb44c8e3a45ba5a73b77f0    glyphicons-halflings-regular.woff2

In the example above, 14032aabd85b43a058cfc7025dd4fa9dd325ea97 is the ID/SHA-1 of the directory that I wanted to explore. In this case, the result was that four files within that directory were being tracked by my Git repo. If the directory had additional files, it would mean those extra files were not being tracked. You can add files using git add <file>... of course.

Changing ImageView source

Or try this one. For me it's working fine:

imageView.setImageDrawable(ContextCompat.getDrawable(this, image));

IntelliJ Organize Imports

In addition to Optimize Imports and Auto Import, which were pointed out by @dave-newton and @ryan-stewart in earlier answers, go to:

  • IDEA <= 13: File menu > Settings > Code Style > Java > Imports
  • IDEA >= 14: File menu > Settings > Editor > Code Style > Java > Imports (thanks to @mathias-bader for the hint!) Settings dialog

There you can fine tune the grouping and order or imports, "Class count to use import with '*'", etc.

Note:
since IDEA 13 you can configure the project default settings from the IDEA "start page": Configure > Project defaults > Settings > .... Then every new project will have those default settings: enter image description here

Cannot implicitly convert type 'int?' to 'int'.

this is because the return type of your method is int and OrdersPerHour is int? (nullable) , you can solve this by returning its value like below:

return OrdersPerHour.Value

also check if its not null to avoid exception like as below:

if(OrdersPerHour != null)
{

    return OrdersPerHour.Value;

}
else
{

  return 0; // depends on your choice

}

but in this case you will have to return some other value in the else part or after the if part otherwise compiler will flag an error that not all paths of code return value.

List All Google Map Marker Images

var pinIcon = new google.maps.MarkerImage(
    "http://chart.apis.google.com/chart?chst=d_map_pin_letter&chld=%E2%80%A2|00D900",
    null, /* size is determined at runtime */
    null, /* origin is 0,0 */
    null, /* anchor is bottom center of the scaled image */
    new google.maps.Size(12, 18)
);

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

I found a better way to find extension by mixing all above answers

public static String getFileExtension(String fileLink) {

        String extension;
        Uri uri = Uri.parse(fileLink);
        String scheme = uri.getScheme();
        if (scheme != null && scheme.equals(ContentResolver.SCHEME_CONTENT)) {
            MimeTypeMap mime = MimeTypeMap.getSingleton();
            extension = mime.getExtensionFromMimeType(CoreApp.getInstance().getContentResolver().getType(uri));
        } else {
            extension = MimeTypeMap.getFileExtensionFromUrl(fileLink);
        }

        return extension;
    }

public static String getMimeType(String fileLink) {
        String type = CoreApp.getInstance().getContentResolver().getType(Uri.parse(fileLink));
        if (!TextUtils.isEmpty(type)) return type;
        MimeTypeMap mime = MimeTypeMap.getSingleton();
        return mime.getMimeTypeFromExtension(FileChooserUtil.getFileExtension(fileLink));
    }

Sort hash by key, return hash in Ruby

I've always used sort_by. You need to wrap the #sort_by output with Hash[] to make it output a hash, otherwise it outputs an array of arrays. Alternatively, to accomplish this you can run the #to_h method on the array of tuples to convert them to a k=>v structure (hash).

hsh ={"a" => 1000, "b" => 10, "c" => 200000}
Hash[hsh.sort_by{|k,v| v}] #or hsh.sort_by{|k,v| v}.to_h

There is a similar question in "How to sort a Ruby Hash by number value?".

How do I remove a key from a JavaScript object?

The delete operator allows you to remove a property from an object.

The following examples all do the same thing.

// Example 1
var key = "Cow";
delete thisIsObject[key]; 

// Example 2
delete thisIsObject["Cow"];

// Example 3
delete thisIsObject.Cow;

If you're interested, read Understanding Delete for an in-depth explanation.

how to open .mat file without using MATLAB?

There's a really nice easy way to do this in Macintosh OsX. A fellow has made a quicklook plugin (command-space) that renders .mat formats so you can view the variables inside etc. Quite useful! https://github.com/jaketmp/matlab-quicklook/releases

How can I make the computer beep in C#?

Try this

Console.WriteLine("\a")

How can I create a Windows .exe (standalone executable) using Java/Eclipse?

Java doesn't natively allow building of an exe, that would defeat its purpose of being cross-platform.

AFAIK, these are your options:

  1. Make a runnable JAR. If the system supports it and is configured appropriately, in a GUI, double clicking the JAR will launch the app. Another option would be to write a launcher shell script/batch file which will start your JAR with the appropriate parameters

  2. There also executable wrappers - see How can I convert my Java program to an .exe file?

See also: Convert Java to EXE: Why, When, When Not and How

performSelector may cause a leak because its selector is unknown

Strange but true: if acceptable (i.e. result is void and you don't mind letting the runloop cycle once), add a delay, even if this is zero:

[_controller performSelector:NSSelectorFromString(@"someMethod")
    withObject:nil
    afterDelay:0];

This removes the warning, presumably because it reassures the compiler that no object can be returned and somehow mismanaged.

Jersey stopped working with InjectionManagerFactory not found

As far as I can see dependencies have changed between 2.26-b03 and 2.26-b04 (HK2 was moved to from compile to testCompile)... there might be some change in the jersey dependencies that has not been completed yet (or which lead to a bug).

However, right now the simple solution is to stick to an older version :-)

set default schema for a sql query

A quick google pointed me to this page. It explains that from sql server 2005 onwards you can set the default schema of a user with the ALTER USER statement. Unfortunately, that means that you change it permanently, so if you need to switch between schemas, you would need to set it every time you execute a stored procedure or a batch of statements. Alternatively, you could use the technique described here.

If you are using sql server 2000 or older this page explains that users and schemas are then equivalent. If you don't prepend your table name with a schema\user, sql server will first look at the tables owned by the current user and then the ones owned by the dbo to resolve the table name. It seems that for all other tables you must prepend the schema\user.

Passing a 2D array to a C++ function

If you want to pass int a[2][3] to void func(int** pp) you need auxiliary steps as follows.

int a[2][3];
int* p[2] = {a[0],a[1]};
int** pp = p;

func(pp);

As the first [2] can be implicitly specified, it can be simplified further as.

int a[][3];
int* p[] = {a[0],a[1]};
int** pp = p;

func(pp);

jQuery: Check if button is clicked

jQuery(':button').click(function () {
    if (this.id == 'button1') {
        alert('Button 1 was clicked');
    }
    else if (this.id == 'button2') {
        alert('Button 2 was clicked');
    }
});

EDIT:- This will work for all buttons.

AsyncTask Android example

Sample AsyncTask example with progress

import android.animation.ObjectAnimator;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.LinearInterpolator;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

public class AsyncTaskActivity extends AppCompatActivity implements View.OnClickListener {

    Button btn;
    ProgressBar progressBar;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(this);
        progressBar = (ProgressBar)findViewById(R.id.pbar);
    }

    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.button1:
                new LongOperation().execute("");
                break;
        }
    }

    private class LongOperation extends AsyncTask<String, Integer, String> {

        @Override
        protected String doInBackground(String... params) {
            Log.d("AsyncTask", "doInBackground");
            for (int i = 0; i < 5; i++) {
                try {
                    Log.d("AsyncTask", "task "+(i + 1));
                    publishProgress(i + 1);
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    Thread.interrupted();
                }
            }
            return "Completed";
        }

        @Override
        protected void onPostExecute(String result) {
            Log.d("AsyncTask", "onPostExecute");
            TextView txt = (TextView) findViewById(R.id.output);
            txt.setText(result);
            progressBar.setProgress(0);
        }

        @Override
        protected void onPreExecute() {
            Log.d("AsyncTask", "onPreExecute");
            TextView txt = (TextView) findViewById(R.id.output);
            txt.setText("onPreExecute");
            progressBar.setMax(500);
            progressBar.setProgress(0);
        }

        @Override
        protected void onProgressUpdate(Integer... values) {
            Log.d("AsyncTask", "onProgressUpdate "+values[0]);
            TextView txt = (TextView) findViewById(R.id.output);
            txt.setText("onProgressUpdate "+values[0]);

            ObjectAnimator animation = ObjectAnimator.ofInt(progressBar, "progress", 100 * values[0]);
            animation.setDuration(1000);
            animation.setInterpolator(new LinearInterpolator());
            animation.start();
        }
    }
}

jQuery send string as POST parameters

I was facing the problem in passing string value to string parameters in Ajax. After so much googling, i have come up with a custom solution as below.

var bar = 'xyz';
var calibri = 'no$libri';

$.ajax({
   type: "POST",
   dataType: "json",
   contentType: "application/json; charset=utf-8",
   url: "http://nakolesah.ru/",
   data: '{ foo: \'' + bar + '\', zoo: \'' + calibri + '\'}',
   success: function(msg){
       alert('wow'+msg);
   },
});

Here, bar and calibri are two string variables and you can pass whatever string value to respective string parameters in web method.

How can I format a nullable DateTime with ToString()?

I think you have to use the GetValueOrDefault-Methode. The behaviour with ToString("yy...") is not defined if the instance is null.

dt2.GetValueOrDefault().ToString("yyy...");

When should I use GC.SuppressFinalize()?

SuppressFinalize should only be called by a class that has a finalizer. It's informing the Garbage Collector (GC) that this object was cleaned up fully.

The recommended IDisposable pattern when you have a finalizer is:

public class MyClass : IDisposable
{
    private bool disposed = false;

    protected virtual void Dispose(bool disposing)
    {
        if (!disposed)
        {
            if (disposing)
            {
                // called via myClass.Dispose(). 
                // OK to use any private object references
            }
            // Release unmanaged resources.
            // Set large fields to null.                
            disposed = true;
        }
    }

    public void Dispose() // Implement IDisposable
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    ~MyClass() // the finalizer
    {
        Dispose(false);
    }
}

Normally, the CLR keeps tabs on objects with a finalizer when they are created (making them more expensive to create). SuppressFinalize tells the GC that the object was cleaned up properly and doesn't need to go onto the finalizer queue. It looks like a C++ destructor, but doesn't act anything like one.

The SuppressFinalize optimization is not trivial, as your objects can live a long time waiting on the finalizer queue. Don't be tempted to call SuppressFinalize on other objects mind you. That's a serious defect waiting to happen.

Design guidelines inform us that a finalizer isn't necessary if your object implements IDisposable, but if you have a finalizer you should implement IDisposable to allow deterministic cleanup of your class.

Most of the time you should be able to get away with IDisposable to clean up resources. You should only need a finalizer when your object holds onto unmanaged resources and you need to guarantee those resources are cleaned up.

Note: Sometimes coders will add a finalizer to debug builds of their own IDisposable classes in order to test that code has disposed their IDisposable object properly.

public void Dispose() // Implement IDisposable
{
    Dispose(true);
#if DEBUG
    GC.SuppressFinalize(this);
#endif
}

#if DEBUG
~MyClass() // the finalizer
{
    Dispose(false);
}
#endif

How to access form methods and controls from a class in C#?

You are trying to access the class as opposed to the object. That statement can be confusing to beginners, but you are effectively trying to open your house door by picking up the door on your house plans.

If you actually wanted to access the form components directly from a class (which you don't) you would use the variable that instantiates your form.

Depending on which way you want to go you'd be better of either sending the text of a control or whatever to a method in your classes eg

public void DoSomethingWithText(string formText)
{
   // do something text in here
}

or exposing properties on your form class and setting the form text in there - eg

string SomeProperty
{
   get 
   {
      return textBox1.Text;
   }
   set
   {
      textBox1.Text = value;
   }
}

Set up adb on Mac OS X

Only for zsh users in iterm2 in macOS

type the following two commands to add the android sdk and platform-tools to your zsh in iterm2 in macOS

echo 'export ANDROID_HOME=/Users/$USER/Library/Android/sdk' >> ~/.zshrc
echo 'export PATH=${PATH}:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools' >> ~/.zshrc

After adding the two command to ~/.zshrc you need to source the zsh.

source ~/.zshrc

SQL Server NOLOCK and joins

I was pretty sure that you need to specify the NOLOCK for each JOIN in the query. But my experience was limited to SQL Server 2005.

When I looked up MSDN just to confirm, I couldn't find anything definite. The below statements do seem to make me think, that for 2008, your two statements above are equivalent though for 2005 it is not the case:

[SQL Server 2008 R2]

All lock hints are propagated to all the tables and views that are accessed by the query plan, including tables and views referenced in a view. Also, SQL Server performs the corresponding lock consistency checks.

[SQL Server 2005]

In SQL Server 2005, all lock hints are propagated to all the tables and views that are referenced in a view. Also, SQL Server performs the corresponding lock consistency checks.

Additionally, point to note - and this applies to both 2005 and 2008:

The table hints are ignored if the table is not accessed by the query plan. This may be caused by the optimizer choosing not to access the table at all, or because an indexed view is accessed instead. In the latter case, accessing an indexed view can be prevented by using the OPTION (EXPAND VIEWS) query hint.

ValueError: unsupported format character while forming strings

For anyone checking this using python 3:

If you want to print the following output "100% correct":

python 3.8: print("100% correct")
python 3.7 and less: print("100%% correct")


A neat programming workaround for compatibility across diff versions of python is shown below:

Note: If you have to use this, you're probably experiencing many other errors... I'd encourage you to upgrade / downgrade python in relevant machines so that they are all compatible.

DevOps is a notable exception to the above -- implementing the following code would indeed be appropriate for specific DevOps / Debugging scenarios.

import sys

if version_info.major==3:
    if version_info.minor>=8:
        my_string = "100% correct"
    else:
        my_string = "100%% correct"

# Finally
print(my_string)

How do I ignore all files in a folder with a Git repository in Sourcetree?

After beating my head on this for at least an hour, I offer this answer to try to expand on the comments some others have made. To ignore a folder/directory, do the following: if you don't have a .gitignore file in the root of your project (that name exactly ".gitignore"), create a dummy text file in the folder you want to exclude. Inside of Source Tree, right click on it and select Ignore. You'll get a popup that looks like this.

enter image description here

Select "Everything underneath" and select the folder you want to ignore from the drop-down list. This will create a .gitignore file in your root directory and put the folder specification in it.

If you do have a .gitignore folder already in your root folder, you could follow the same approach above, or you can just edit the .gitignore file and add the folder you want to exclude. It's just a text file. Note that it uses forward slashes in path names rather than backslashes, as we Windows users are accustomed to. I tried creating a .gitignore text file by hand in Windows Explorer, but it didn't let me create a file without a name (i.e. with only the extension).

Note that adding the .gitignore and the file specification will have no effect on files that are already being tracked. If you're already tracking these, you'll have to stop tracking them. (Right-click on the folder or file and select Stop Tracking.) You'll then see them change from having a green/clean or amber/changed icon to a red/removed icon. On your next commit the files will be removed from the repository and thereafter appear with a blue/ignored icon. Another contributor asked why Ignore was disabled for particular files and I believe it was because he was trying to ignore a file that was already being tracked. You can only ignore a file that has a blue question mark icon.

Recommended way to get hostname in Java

InetAddress.getLocalHost().getHostName() is the more portable way.

exec("hostname") actually calls out to the operating system to execute the hostname command.

Here are a couple other related answers on SO:

EDIT: You should take a look at A.H.'s answer or Arnout Engelen's answer for details on why this might not work as expected, depending on your situation. As an answer for this person who specifically requested portable, I still think getHostName() is fine, but they bring up some good points that should be considered.

How to disable scientific notation?

format(99999999,scientific = F)

gives

99999999

Failed to install android-sdk: "java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema"

Update 2019-10:

As stated in the issue tracker, Google has been working on a new Android SDK Command-line Tools release that runs on current JVMs (9, 10, 11+) and does not depend on deprecated JAXB EE modules!

You can download and use the new Android SDK Command-line Tools inside Android Studio or by manually downloading them from the Google servers:

For the latest versions check the URLs inside the repository.xml.

If you manually unpack the command line tools, take care of placing them in a subfolder inside your $ANDROID_HOME (e.g. $ANDROID_HOME/cmdline-tools/...).

How to center align the ActionBar title in Android?

Best and easiest way, specifically for those who just want text view with gravity center without any xml layout.

AppCompatTextView mTitleTextView = new AppCompatTextView(getApplicationContext());
        mTitleTextView.setSingleLine();
        ActionBar.LayoutParams layoutParams = new ActionBar.LayoutParams(ActionBar.LayoutParams.WRAP_CONTENT, ActionBar.LayoutParams.WRAP_CONTENT);
        layoutParams.gravity = Gravity.CENTER;
        actionBar.setCustomView(mTitleTextView, layoutParams);
        actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM | ActionBar.DISPLAY_HOME_AS_UP);
        mTitleTextView.setText(text);
        mTitleTextView.setTextAppearance(getApplicationContext(), android.R.style.TextAppearance_Medium);

Generating random, unique values C#

I'm calling NewNumber() regularly, but the problem is I often get repeated numbers.

Random.Next doesn't guarantee the number to be unique. Also your range is from 0 to 10 and chances are you will get duplicate values. May be you can setup a list of int and insert random numbers in the list after checking if it doesn't contain the duplicate. Something like:

public Random a = new Random(); // replace from new Random(DateTime.Now.Ticks.GetHashCode());
                                // Since similar code is done in default constructor internally
public List<int> randomList = new List<int>();
int MyNumber = 0;
private void NewNumber()
{
    MyNumber = a.Next(0, 10);
    if (!randomList.Contains(MyNumber))
        randomList.Add(MyNumber);
}

Regex for Comma delimited list

I had a slightly different requirement, to parse an encoded dictionary/hashtable with escaped commas, like this:

"1=This is something, 2=This is something,,with an escaped comma, 3=This is something else"

I think this is an elegant solution, with a trick that avoids a lot of regex complexity:

if (string.IsNullOrEmpty(encodedValues))
{
    return null;
}
else
{
    var retVal = new Dictionary<int, string>();
    var reFields = new Regex(@"([0-9]+)\=(([A-Za-z0-9\s]|(,,))+),");
    foreach (Match match in reFields.Matches(encodedValues + ","))
    {
        var id = match.Groups[1].Value;
        var value = match.Groups[2].Value;
        retVal[int.Parse(id)] = value.Replace(",,", ",");
    }
    return retVal;
}

I think it can be adapted to the original question with an expression like @"([0-9]+),\s?" and parse on Groups[0].

I hope it's helpful to somebody and thanks for the tips on getting it close to there, especially Asaph!

How to suppress binary file matching results in grep

There are three options, that you can use. -I is to exclude binary files in grep. Other are for line numbers and file names.

grep -I -n -H 


-I -- process a binary file as if it did not contain matching data; 
-n -- prefix each line of output with the 1-based line number within its input file
-H -- print the file name for each match

So this might be a way to run grep:

grep -InH your-word *

How to check if two words are anagrams

Some other solution without sorting.

public static boolean isAnagram(String s1, String s2){
    //case insensitive anagram

    StringBuffer sb = new StringBuffer(s2.toLowerCase());
    for (char c: s1.toLowerCase().toCharArray()){
        if (Character.isLetter(c)){

            int index = sb.indexOf(String.valueOf(c));
            if (index == -1){
                //char does not exist in other s2
                return false;
            }
            sb.deleteCharAt(index);
        }
    }
    for (char c: sb.toString().toCharArray()){
        //only allow whitespace as left overs
        if (!Character.isWhitespace(c)){
            return false;
        }
    }
    return true;
}

What is the purpose of a self executing function in javascript?

Scope isolation, maybe. So that the variables inside the function declaration don't pollute the outer namespace.

Of course, on half the JS implementations out there, they will anyway.

Formula px to dp, dp to px android

variation on ct_robs answer above, if you are using integers, that not only avoids divide by 0 it also produces a usable result on small devices:

in integer calculations involving division for greatest precision multiply first before dividing to reduce truncation effects.

px = dp * dpi / 160
dp = px * 160 / dpi

5 * 120 = 600 / 160 = 3

instead of

5 * (120 / 160 = 0) = 0

if you want rounded result do this

px = (10 * dp * dpi / 160 + 5) / 10
dp = (10 * px * 160 / dpi + 5) / 10

10 * 5 * 120 = 6000 / 160 = 37 + 5 = 42 / 10 = 4

Vue component event after render

updated might be what you're looking for. https://vuejs.org/v2/api/#updated

Check if boolean is true?

Almost everyone I've seen expressing an opinion prefers

if (foo)
{
}

Indeed, I've seen many people criticize the explicit comparison, and I may even have done so myself before now. I'd say the "short" style is idiomatic.

EDIT:

Note that this doesn't mean that line of code is always incorrect. Consider:

bool? maybeFoo = GetSomeNullableBooleanValue();
if (maybeFoo == true)
{
    ...
}

That will compile, but without the "== true" it won't, as there's no implicit conversion from bool? to bool.

Unit testing click event in Angular

I'm using Angular 6. I followed Mav55's answer and it worked. However I wanted to make sure if fixture.detectChanges(); was really necessary so I removed it and it still worked. Then I removed tick(); to see if it worked and it did. Finally I removed the test from the fakeAsync() wrap, and surprise, it worked.

So I ended up with this:

it('should call onClick method', () => {
  const onClickMock = spyOn(component, 'onClick');
  fixture.debugElement.query(By.css('button')).triggerEventHandler('click', null);
  expect(onClickMock).toHaveBeenCalled();
});

And it worked just fine.

Why does multiplication repeats the number several times?

Should work:

In [1]: price = 1*9

In [2]: price
Out[2]: 9

form action with javascript

Absolutely valid.

    <form action="javascript:alert('Hello there, I am being submitted');">
        <button type="submit">
            Let's do it
        </button>
    </form>
    <!-- Tested in Firefox, Chrome, Edge and Safari -->

So for a short answer: yes, this is an option, and a nice one. It says "when submitted, please don't go anywhere, just run this script" - quite to the point.

A minor improvement

To let the event handler know which form we're dealing with, it would seem an obvious way to pass on the sender object:

    <form action="javascript:myFunction(this)">  <!-- should work, but it won't -->

But instead, it will give you undefined. You can't access it because javascript: links live in a separate scope. Therefore I'd suggest the following format, it's only 13 characters more and works like a charm:

    <form action="javascript:;" onsubmit="myFunction(this)">  <!-- now you have it! -->

... now you can access the sender form properly. (You can write a simple "#" as action, it's quite common - but it has a side effect of scrolling to the top when submitting.)

Again, I like this approach because it's effortless and self-explaining. No "return false", no jQuery/domReady, no heavy weapons. It just does what it seems to do. Surely other methods work too, but for me, this is The Way Of The Samurai.

A note on validation

Forms only get submitted if their onsubmit event handler returns something truthy, so you can easily run some preemptive checks:

    <form action="/something.php" onsubmit="return isMyFormValid(this)">

Now isMyFormValid will run first, and if it returns false, server won't even be bothered. Needless to say, you will have to validate on server side too, and that's the more important one. But for quick and convenient early detection this is fine.

Socket.io + Node.js Cross-Origin Request Blocked

Using same version for both socket.io and socket.io-client fixed my issue.

MIME types missing in IIS 7 for ASP.NET - 404.17

There are two reasons you might get this message:

  1. ASP.Net is not configured. For this run from Administrator command %FrameworkDir%\%FrameworkVersion%\aspnet_regiis -i. Read the message carefully. On Windows8/IIS8 it may say that this is no longer supported and you may have to use Turn Windows Features On/Off dialog in Install/Uninstall a Program in Control Panel.
  2. Another reason this may happen is because your App Pool is not configured correctly. For example, you created website for WordPress and you also want to throw in few aspx files in there, WordPress creates app pool that says don't run CLR stuff. To fix this just open up App Pool and enable CLR.

Get full path of a file with FileUpload Control

FileUpload will never give you the full path for security reasons.

Blurring an image via CSS?

CSS3 filters currently work only in webkit browsers (safari and chrome).

Passing javascript variable to html textbox

<form name="input" action="some.php" method="post">
 <input type="text" name="user" id="mytext">
 <input type="submit" value="Submit">
</form>

<script>
  var w = someValue;
document.getElementById("mytext").value = w;

</script>

//php on some.php page

echo $_POST['user'];

Switching between GCC and Clang/LLVM using CMake

System wide C++ change on Ubuntu:

sudo apt-get install clang
sudo update-alternatives --config c++

Will print something like this:

  Selection    Path              Priority   Status
------------------------------------------------------------
* 0            /usr/bin/g++       20        auto mode
  1            /usr/bin/clang++   10        manual mode
  2            /usr/bin/g++       20        manual mode

Then just select clang++.

How to measure time elapsed on Javascript?

The Date documentation states that :

The JavaScript date is based on a time value that is milliseconds since midnight January 1, 1970, UTC

Click on start button then on end button. It will show you the number of seconds between the 2 clicks.

The milliseconds diff is in variable timeDiff. Play with it to find seconds/minutes/hours/ or what you need

_x000D_
_x000D_
var startTime, endTime;_x000D_
_x000D_
function start() {_x000D_
  startTime = new Date();_x000D_
};_x000D_
_x000D_
function end() {_x000D_
  endTime = new Date();_x000D_
  var timeDiff = endTime - startTime; //in ms_x000D_
  // strip the ms_x000D_
  timeDiff /= 1000;_x000D_
_x000D_
  // get seconds _x000D_
  var seconds = Math.round(timeDiff);_x000D_
  console.log(seconds + " seconds");_x000D_
}
_x000D_
<button onclick="start()">Start</button>_x000D_
_x000D_
<button onclick="end()">End</button>
_x000D_
_x000D_
_x000D_

OR another way of doing it for modern browser

Using performance.now() which returns a value representing the time elapsed since the time origin. This value is a double with microseconds in the fractional.

The time origin is a standard time which is considered to be the beginning of the current document's lifetime.

_x000D_
_x000D_
var startTime, endTime;_x000D_
_x000D_
function start() {_x000D_
  startTime = performance.now();_x000D_
};_x000D_
_x000D_
function end() {_x000D_
  endTime = performance.now();_x000D_
  var timeDiff = endTime - startTime; //in ms _x000D_
  // strip the ms _x000D_
  timeDiff /= 1000; _x000D_
  _x000D_
  // get seconds _x000D_
  var seconds = Math.round(timeDiff);_x000D_
  console.log(seconds + " seconds");_x000D_
}
_x000D_
<button onclick="start()">Start</button>_x000D_
<button onclick="end()">End</button>
_x000D_
_x000D_
_x000D_

How to create and handle composite primary key in JPA

You can make an Embedded class, which contains your two keys, and then have a reference to that class as EmbeddedId in your Entity.

You would need the @EmbeddedId and @Embeddable annotations.

@Entity
public class YourEntity {
    @EmbeddedId
    private MyKey myKey;

    @Column(name = "ColumnA")
    private String columnA;

    /** Your getters and setters **/
}
@Embeddable
public class MyKey implements Serializable {

    @Column(name = "Id", nullable = false)
    private int id;

    @Column(name = "Version", nullable = false)
    private int version;

    /** getters and setters **/
}

Another way to achieve this task is to use @IdClass annotation, and place both your id in that IdClass. Now you can use normal @Id annotation on both the attributes

@Entity
@IdClass(MyKey.class)
public class YourEntity {
   @Id
   private int id;
   @Id
   private int version;

}

public class MyKey implements Serializable {
   private int id;
   private int version;
}

Subtract minute from DateTime in SQL Server 2005

Have you tried

SELECT DATEADD(mi, -15,'2000-01-01 08:30:00')

DATEDIFF is the difference between 2 dates.

Javascript decoding html entities

Using jQuery the easiest will be:

var text = '&lt;p&gt;name&lt;/p&gt;&lt;p&gt;&lt;span style="font-size:xx-small;"&gt;ajde&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;da&lt;/em&gt;&lt;/p&gt;';

var output = $("<div />").html(text).text();
console.log(output);

DEMO: http://jsfiddle.net/LKGZx/

int to string in MySQL

select t2.* 
from t1 join t2 on t2.url='site.com/path/%' + cast(t1.id as varchar)  + '%/more' 
where t1.id > 9000

Using concat like suggested is even better though

Read file-contents into a string in C++

The most efficient, but not the C++ way would be:

   FILE* f = fopen(filename, "r");

   // Determine file size
   fseek(f, 0, SEEK_END);
   size_t size = ftell(f);

   char* where = new char[size];

   rewind(f);
   fread(where, sizeof(char), size, f);

   delete[] where;

#EDIT - 2

Just tested the std::filebuf variant also. Looks like it can be called the best C++ approach, even though it's not quite a C++ approach, but more a wrapper. Anyway, here is the chunk of code that works almost as fast as plain C does.

   std::ifstream file(filename, std::ios::binary);
   std::streambuf* raw_buffer = file.rdbuf();

   char* block = new char[size];
   raw_buffer->sgetn(block, size);
   delete[] block;

I've done a quick benchmark here and the results are following. Test was done on reading a 65536K binary file with appropriate (std::ios:binary and rb) modes.

[==========] Running 3 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 4 tests from IO
[ RUN      ] IO.C_Kotti
[       OK ] IO.C_Kotti (78 ms)
[ RUN      ] IO.CPP_Nikko
[       OK ] IO.CPP_Nikko (106 ms)
[ RUN      ] IO.CPP_Beckmann
[       OK ] IO.CPP_Beckmann (1891 ms)
[ RUN      ] IO.CPP_Neil
[       OK ] IO.CPP_Neil (234 ms)
[----------] 4 tests from IO (2309 ms total)

[----------] Global test environment tear-down
[==========] 4 tests from 1 test case ran. (2309 ms total)
[  PASSED  ] 4 tests.

Read tab-separated file line into array

If you really want to split every word (bash meaning) into a different array index completely changing the array in every while loop iteration, @ruakh's answer is the correct approach. But you can use the read property to split every read word into different variables column1, column2, column3 like in this code snippet

while IFS=$'\t' read -r column1 column2 column3 ; do
  printf "%b\n" "column1<${column1}>"
  printf "%b\n" "column2<${column2}>"
  printf "%b\n" "column3<${column3}>"
done < "myfile"

to reach a similar result avoiding array index access and improving your code readability by using meaningful variable names (of course using columnN is not a good idea to do so).

How to convert milliseconds to seconds with precision

Why don't you simply try

System.out.println(1500/1000.0);
System.out.println(500/1000.0);

Android How to adjust layout in Full Screen Mode when softkeyboard is visible

1) Create KeyboardHeightHelper:

public class KeyboardHeightHelper {

    private final View decorView;
    private int lastKeyboardHeight = -1;

    public KeyboardHeightHelper(Activity activity, View activityRootView, OnKeyboardHeightChangeListener listener) {
        this.decorView = activity.getWindow().getDecorView();
        activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(() -> {
            int keyboardHeight = getKeyboardHeight();
            if (lastKeyboardHeight != keyboardHeight) {
                lastKeyboardHeight = keyboardHeight;
                listener.onKeyboardHeightChange(keyboardHeight);
            }
        });
    }

    private int getKeyboardHeight() {
        Rect rect = new Rect();
        decorView.getWindowVisibleDisplayFrame(rect);
        return decorView.getHeight() - rect.bottom;
    }

    public interface OnKeyboardHeightChangeListener {
        void onKeyboardHeightChange(int keyboardHeight);
    }
}

2) Let your activity be full screen:

activity.getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);

3) Listen for keyboard height changes and add bottom padding for your view:

View rootView = activity.findViewById(R.id.root); // your root view or any other you want to resize
KeyboardHeightHelper effectiveHeightHelper = new KeyboardHeightHelper(
        activity, 
        rootView,
        keyboardHeight -> rootView.setPadding(0, 0, 0, keyboardHeight));

So, each time keyboard will appear on the screen - bottom padding for your view will change, and content will be rearranged.

What is the maximum length of a valid email address?

320

And the segments look like this

{64}@{255}

64 + 1 + 255 = 320

You should also read this if you are validating emails

http://haacked.com/archive/2007/08/21/i-knew-how-to-validate-an-email-address-until-i.aspx

Date in to UTC format Java

java.time

It’s about time someone provides the modern answer. The modern solution uses java.time, the modern Java date and time API. The classes SimpleDateFormat and Date used in the question and in a couple of the other answers are poorly designed and long outdated, the former in particular notoriously troublesome. TimeZone is poorly designed to. I recommend you avoid those.

    ZoneId utc = ZoneId.of("Etc/UTC");
    DateTimeFormatter targetFormatter = DateTimeFormatter.ofPattern(
            "MM/dd/yyyy hh:mm:ss a zzz", Locale.ENGLISH);

    String itsAlarmDttm = "2013-10-22T01:37:56";
    ZonedDateTime utcDateTime = LocalDateTime.parse(itsAlarmDttm)
            .atZone(ZoneId.systemDefault())
            .withZoneSameInstant(utc);
    String formatterUtcDateTime = utcDateTime.format(targetFormatter);
    System.out.println(formatterUtcDateTime);

When running in my time zone, Europe/Copenhagen, the output is:

10/21/2013 11:37:56 PM UTC

I have assumed that the string you got was in the default time zone of your JVM, a fragile assumption since that default setting can be changed at any time from another part of your program or another programming running in the same JVM. If you can, instead specify time zone explicitly, for example ZoneId.of("Europe/Podgorica") or ZoneId.of("Asia/Kolkata").

I am exploiting the fact that you string is in ISO 8601 format, the format the the modern classes parse as their default, that is, without any explicit formatter.

I am using a ZonedDateTime for the result date-time because it allows us to format it with UTC in the formatted string to eliminate any and all doubt. For other purposes one would typically have wanted an OffsetDateTime or an Instant instead.

Links

Mac OS X - EnvironmentError: mysql_config not found

If you have installed mysql using Homebrew by specifying a version then mysql_config would be present here. - /usr/local/Cellar/[email protected]/5.6.47/bin

you can find the path of the sql bin by using ls command in /usr/local/ directory

/usr/local/Cellar/[email protected]/5.6.47/bin

Add the path to bash profile like this.

nano ~/.bash_profile

export PATH="/usr/local/Cellar/[email protected]/5.6.47/bin:$PATH"

java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer in java 1.6

The number of results can (theoretically) be greater than the range of an integer. I would refactor the code and work with the returned long value instead.

Create a OpenSSL certificate on Windows

If you're on windows and using apache, maybe via WAMP or the Drupal stack installer, you can additionally download the git for windows package, which includes many useful linux command line tools, one of which is openssl.

The following command creates the self signed certificate and key needed for apache and works fine in windows:

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout privatekey.key -out certificate.crt

How do you monitor network traffic on the iPhone?

Without knowing exactly what your requirements are, here's what I did to see packts go by from the iPhone: Connect a mac on ethernet, share its network over airport and connect the iPhone to that wireless network. Run Wireshark or Packet Peeper on the mac.

Failed to fetch URL https://dl-ssl.google.com/android/repository/addons_list-1.xml, reason: Connection to https://dl-ssl.google.com refused

just run the android sdk manager , go to tools then obtions and a new window will apears mark the three checkboxes at the bottom and close it it worked for me

What is the difference between a hash join and a merge join (Oracle RDBMS )?

A "sort merge" join is performed by sorting the two data sets to be joined according to the join keys and then merging them together. The merge is very cheap, but the sort can be prohibitively expensive especially if the sort spills to disk. The cost of the sort can be lowered if one of the data sets can be accessed in sorted order via an index, although accessing a high proportion of blocks of a table via an index scan can also be very expensive in comparison to a full table scan.

A hash join is performed by hashing one data set into memory based on join columns and reading the other one and probing the hash table for matches. The hash join is very low cost when the hash table can be held entirely in memory, with the total cost amounting to very little more than the cost of reading the data sets. The cost rises if the hash table has to be spilled to disk in a one-pass sort, and rises considerably for a multipass sort.

(In pre-10g, outer joins from a large to a small table were problematic performance-wise, as the optimiser could not resolve the need to access the smaller table first for a hash join, but the larger table first for an outer join. Consequently hash joins were not available in this situation).

The cost of a hash join can be reduced by partitioning both tables on the join key(s). This allows the optimiser to infer that rows from a partition in one table will only find a match in a particular partition of the other table, and for tables having n partitions the hash join is executed as n independent hash joins. This has the following effects:

  1. The size of each hash table is reduced, hence reducing the maximum amount of memory required and potentially removing the need for the operation to require temporary disk space.
  2. For parallel query operations the amount of inter-process messaging is vastly reduced, reducing CPU usage and improving performance, as each hash join can be performed by one pair of PQ processes.
  3. For non-parallel query operations the memory requirement is reduced by a factor of n, and the first rows are projected from the query earlier.

You should note that hash joins can only be used for equi-joins, but merge joins are more flexible.

In general, if you are joining large amounts of data in an equi-join then a hash join is going to be a better bet.

This topic is very well covered in the documentation.

http://download.oracle.com/docs/cd/B28359_01/server.111/b28274/optimops.htm#i51523

12.1 docs: https://docs.oracle.com/database/121/TGSQL/tgsql_join.htm

HTML SELECT - Change selected option by VALUE using JavaScript

document.getElementById('drpSelectSourceLibrary').value = 'Seven';

How to export plots from matplotlib with transparent background?

Png files can handle transparency. So you could use this question Save plot to image file instead of displaying it using Matplotlib so as to save you graph as a png file.

And if you want to turn all white pixel transparent, there's this other question : Using PIL to make all white pixels transparent?

If you want to turn an entire area to transparent, then there's this question: And then use the PIL library like in this question Python PIL: how to make area transparent in PNG? so as to make your graph transparent.

Vim: insert the same characters across multiple lines

  1. Ctrl + v to go to visual block mode
  2. Select the lines using the up and down arrow
  3. Enter lowercase 3i (press lowercase I three times)
  4. I (press capital I. That will take you into insert mode.)
  5. Write the text you want to add
  6. Esc
  7. Press the down arrow

SQL UPDATE SET one column to be equal to a value in a related table referenced by a different column?

I don't know if you've run into the same problem than me on MySQL Workbench but running the query with the INNER JOIN after the FROM statement didn't work for me. I was unable to run the query because the program complained about the FROM statement.

So in order to make the query work I changed it to

UPDATE table1 INNER JOIN table2 on table1.column1 = table2.column1
SET table1.column2 = table2.column4
WHERE table1.column3 = 'randomCondition';

instead of

UPDATE a
FROM table1 a INNER JOIN table2 b on a.column1 = b.column1
SET a.column2 = b.column4
WHERE a.column3 = 'randomCondition';

I guess my solution is the right syntax for MySQL.

How do I create a comma-separated list from an array in PHP?

If doing quoted answers, you can do

$commaList = '"'.implode( '" , " ', $fruit). '"';

the above assumes that fruit is non-null. If you don't want to make that assumption you can use an if-then-else statement or ternary (?:) operator.

Truncate number to two decimal places without rounding

Roll your own toFixed function: for positive values Math.floor works fine.

function toFixed(num, fixed) {
    fixed = fixed || 0;
    fixed = Math.pow(10, fixed);
    return Math.floor(num * fixed) / fixed;
}

For negative values Math.floor is round of the values. So you can use Math.ceil instead.

Example,

Math.ceil(-15.778665 * 10000) / 10000 = -15.7786
Math.floor(-15.778665 * 10000) / 10000 = -15.7787 // wrong.

How do you specify a different port number in SQL Management Studio?

127.0.0.1,6283

Add a comma between the ip and port

How to list all properties of a PowerShell object

If you want to know what properties (and methods) there are:

Get-WmiObject -Class "Win32_computersystem" | Get-Member

What is the role of "Flatten" in Keras?

If you read the Keras documentation entry for Dense, you will see that this call:

Dense(16, input_shape=(5,3))

would result in a Dense network with 3 inputs and 16 outputs which would be applied independently for each of 5 steps. So, if D(x) transforms 3 dimensional vector to 16-d vector, what you'll get as output from your layer would be a sequence of vectors: [D(x[0,:]), D(x[1,:]),..., D(x[4,:])] with shape (5, 16). In order to have the behavior you specify you may first Flatten your input to a 15-d vector and then apply Dense:

model = Sequential()
model.add(Flatten(input_shape=(3, 2)))
model.add(Dense(16))
model.add(Activation('relu'))
model.add(Dense(4))
model.compile(loss='mean_squared_error', optimizer='SGD')

EDIT: As some people struggled to understand - here you have an explaining image:

enter image description here

Where in memory are my variables stored in C?

For those future visitors who may be interested in knowing about those memory segments, I am writing important points about 5 memory segments in C:

Some heads up:

  1. Whenever a C program is executed some memory is allocated in the RAM for the program execution. This memory is used for storing the frequently executed code (binary data), program variables, etc. The below memory segments talks about the same:
  2. Typically there are three types of variables:
    • Local variables (also called as automatic variables in C)
    • Global variables
    • Static variables
    • You can have global static or local static variables, but the above three are the parent types.

5 Memory Segments in C:

1. Code Segment

  • The code segment, also referred as the text segment, is the area of memory which contains the frequently executed code.
  • The code segment is often read-only to avoid risk of getting overridden by programming bugs like buffer-overflow, etc.
  • The code segment does not contain program variables like local variable (also called as automatic variables in C), global variables, etc.
  • Based on the C implementation, the code segment can also contain read-only string literals. For example, when you do printf("Hello, world") then string "Hello, world" gets created in the code/text segment. You can verify this using size command in Linux OS.
  • Further reading

Data Segment

The data segment is divided in the below two parts and typically lies below the heap area or in some implementations above the stack, but the data segment never lies between the heap and stack area.

2. Uninitialized data segment

  • This segment is also known as bss.
  • This is the portion of memory which contains:
    1. Uninitialized global variables (including pointer variables)
    2. Uninitialized constant global variables.
    3. Uninitialized local static variables.
  • Any global or static local variable which is not initialized will be stored in the uninitialized data segment
  • For example: global variable int globalVar; or static local variable static int localStatic; will be stored in the uninitialized data segment.
  • If you declare a global variable and initialize it as 0 or NULL then still it would go to uninitialized data segment or bss.
  • Further reading

3. Initialized data segment

  • This segment stores:
    1. Initialized global variables (including pointer variables)
    2. Initialized constant global variables.
    3. Initialized local static variables.
  • For example: global variable int globalVar = 1; or static local variable static int localStatic = 1; will be stored in initialized data segment.
  • This segment can be further classified into initialized read-only area and initialized read-write area. Initialized constant global variables will go in the initialized read-only area while variables whose values can be modified at runtime will go in the initialized read-write area.
  • The size of this segment is determined by the size of the values in the program's source code, and does not change at run time.
  • Further reading

4. Stack Segment

  • Stack segment is used to store variables which are created inside functions (function could be main function or user-defined function), variable like
    1. Local variables of the function (including pointer variables)
    2. Arguments passed to function
    3. Return address
  • Variables stored in the stack will be removed as soon as the function execution finishes.
  • Further reading

5. Heap Segment

  • This segment is to support dynamic memory allocation. If the programmer wants to allocate some memory dynamically then in C it is done using the malloc, calloc, or realloc methods.
  • For example, when int* prt = malloc(sizeof(int) * 2) then eight bytes will be allocated in heap and memory address of that location will be returned and stored in ptr variable. The ptr variable will be on either the stack or data segment depending on the way it is declared/used.
  • Further reading

If table exists drop table then create it, if it does not exist just create it

Just put DROP TABLE IF EXISTS `tablename`; before your CREATE TABLE statement.

That statement drops the table if it exists but will not throw an error if it does not.

How to put a List<class> into a JSONObject and then read that object?

You could use a JSON serializer/deserializer like flexjson to do the conversion for you.

How to find all occurrences of an element in a list

While not a solution for lists directly, numpy really shines for this sort of thing:

import numpy as np
values = np.array([1,2,3,1,2,4,5,6,3,2,1])
searchval = 3
ii = np.where(values == searchval)[0]

returns:

ii ==>array([2, 8])

This can be significantly faster for lists (arrays) with a large number of elements vs some of the other solutions.

Android: Pass data(extras) to a fragment

I prefer Serializable = no boilerplate code. For passing data to other Fragments or Activities the speed difference to a Parcelable does not matter.

I would also always provide a helper method for a Fragment or Activity, this way you always know, what data has to be passed. Here an example for your ListMusicFragment:

private static final String EXTRA_MUSIC_LIST = "music_list";

public static ListMusicFragment createInstance(List<Music> music) {
    ListMusicFragment fragment = new ListMusicFragment();
    Bundle bundle = new Bundle();
    bundle.putSerializable(EXTRA_MUSIC_LIST, music);
    fragment.setArguments(bundle);
    return fragment;
}

@Override
public View onCreateView(...) { 
    ...
    Bundle bundle = intent.getArguments();
    List<Music> musicList = (List<Music>)bundle.getSerializable(EXTRA_MUSIC_LIST);
    ...
}

Convert float to double without losing precision

Does this work?

float flt = 145.664454;

Double dbl = 0.0;
dbl += flt;

org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 15

I've had the same problem when running my spring boot application with tomcat7:run

It gives error with the following dependency in maven pom.xml:

    <dependency>
        <groupId>org.junit.vintage</groupId>
        <artifactId>junit-vintage-engine</artifactId>
    </dependency>
SEVERE: Unable to process Jar entry [module-info.class] from Jar [jar:file:/.m2/repository/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/] for annotations
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19

Jul 09, 2020 1:28:09 PM org.apache.catalina.startup.ContextConfig processAnnotationsJar
SEVERE: Unable to process Jar entry [module-info.class] from Jar [jar:file:/.m2/repository/org/apiguardian/apiguardian-api/1.1.0/apiguardian-api-1.1.0.jar!/] for annotations
org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 19

But when I correctly specify it in test scope, it does not give error:

    <dependency>
        <groupId>org.junit.vintage</groupId>
        <artifactId>junit-vintage-engine</artifactId>
        <scope>test</scope>
    </dependency>

Best way to change font colour halfway through paragraph?

Nornally the tag is used for that, with a change in style.

Like <p>This is my text <span class="highlight"> and these words are different</span></p>,

You set the css in the header (or rather, in a separate css file) to make your "highlight" text assume the color you wish.

(e.g.: with

<style type="text/css">
  .highlight {color: orange}

</style>

in the header. Avoid using the tag <font /> for that at all costs. :-)

Skip first entry in for loop in python?

Here is a more general generator function that skips any number of items from the beginning and end of an iterable:

def skip(iterable, at_start=0, at_end=0):
    it = iter(iterable)
    for x in itertools.islice(it, at_start):
        pass
    queue = collections.deque(itertools.islice(it, at_end))
    for x in it:
        queue.append(x)
        yield queue.popleft()

Example usage:

>>> list(skip(range(10), at_start=2, at_end=2))
[2, 3, 4, 5, 6, 7]

Print a file, skipping the first X lines, in Bash

If you want to skip first two line:

tail -n +3 <filename>

If you want to skip first x line:

tail -n +$((x+1)) <filename>

Apply function to each column in a data frame observing each columns existing data type

If you want to learn your data summary (df) provides the min, 1st quantile, median and mean, 3rd quantile and max of numerical columns and the frequency of the top levels of the factor columns.

Celery Received unregistered task of type (run example)

I also had the same problem; I added

CELERY_IMPORTS=("mytasks")

in my celeryconfig.py file to solve it.

How to copy commits from one branch to another?

git cherry-pick : Apply the changes introduced by some existing commits

Assume we have branch A with (X, Y, Z) commits. We need to add these commits to branch B. We are going to use the cherry-pick operations.

When we use cherry-pick, we should add commits on branch B in the same chronological order that the commits appear in Branch A.

cherry-pick does support a range of commits, but if you have merge commits in that range, it gets really complicated

git checkout B
git cherry-pick SHA-COMMIT-X
git cherry-pick SHA-COMMIT-Y
git cherry-pick SHA-COMMIT-Z

Example of workflow :

enter image description here

We can use cherry-pick with options

-e or --edit : With this option, git cherry-pick will let you edit the commit message prior to committing.

-n or --no-commit : Usually the command automatically creates a sequence of commits. This flag applies the changes necessary to cherry-pick each named commit to your working tree and the index, without making any commit. In addition, when this option is used, your index does not have to match the HEAD commit. The cherry-pick is done against the beginning state of your index.

Here an interesting article concerning cherry-pick.

How to get first character of string?

var str="stack overflow";

firstChar  = str.charAt(0);

secondChar = str.charAt(1);

Tested in IE6+, FF, Chrome, safari.

What is the default Precision and Scale for a Number in Oracle?

Actually, you can always test it by yourself.

CREATE TABLE CUSTOMERS ( CUSTOMER_ID NUMBER NOT NULL, JOIN_DATE DATE NOT NULL, CUSTOMER_STATUS VARCHAR2(8) NOT NULL, CUSTOMER_NAME VARCHAR2(20) NOT NULL, CREDITRATING VARCHAR2(10) ) ;

select column_name, data_type, nullable, data_length, data_precision, data_scale from user_tab_columns where table_name ='CUSTOMERS';

SQL Server : trigger how to read value for Insert, Update, Delete

Here is the syntax to create a trigger:

CREATE TRIGGER trigger_name
ON { table | view }
[ WITH ENCRYPTION ]
{
    { { FOR | AFTER | INSTEAD OF } { [ INSERT ] [ , ] [ UPDATE ] [ , ] [ DELETE ] }
        [ WITH APPEND ]
        [ NOT FOR REPLICATION ]
        AS
        [ { IF UPDATE ( column )
            [ { AND | OR } UPDATE ( column ) ]
                [ ...n ]
        | IF ( COLUMNS_UPDATED ( ) { bitwise_operator } updated_bitmask )
                { comparison_operator } column_bitmask [ ...n ]
        } ]
        sql_statement [ ...n ]
    }
} 

If you want to use On Update you only can do it with the IF UPDATE ( column ) section. That's not possible to do what you are asking.

How can I implement a tree in Python?

anytree

I recommend https://pypi.python.org/pypi/anytree (I am the author)

Example

from anytree import Node, RenderTree

udo = Node("Udo")
marc = Node("Marc", parent=udo)
lian = Node("Lian", parent=marc)
dan = Node("Dan", parent=udo)
jet = Node("Jet", parent=dan)
jan = Node("Jan", parent=dan)
joe = Node("Joe", parent=dan)

print(udo)
Node('/Udo')
print(joe)
Node('/Udo/Dan/Joe')

for pre, fill, node in RenderTree(udo):
    print("%s%s" % (pre, node.name))
Udo
+-- Marc
¦   +-- Lian
+-- Dan
    +-- Jet
    +-- Jan
    +-- Joe

print(dan.children)
(Node('/Udo/Dan/Jet'), Node('/Udo/Dan/Jan'), Node('/Udo/Dan/Joe'))

Features

anytree has also a powerful API with:

  • simple tree creation
  • simple tree modification
  • pre-order tree iteration
  • post-order tree iteration
  • resolve relative and absolute node paths
  • walking from one node to an other.
  • tree rendering (see example above)
  • node attach/detach hookups

How to get the directory of the currently running file?

Sometimes this is enough, the first argument will always be the file path

package main

import (
    "fmt"
    "os"
)


func main() {
    fmt.Println(os.Args[0])

    // or
    dir, _ := os.Getwd()
    fmt.Println(dir)
}

When using .net MVC RadioButtonFor(), how do you group so only one selection can be made?

In my case, I had a collection of radio buttons that needed to be in a group. I just included a 'Selected' property in the model. Then, in the loop to output the radiobuttons just do...

@Html.RadioButtonFor(m => Model.Selected, Model.Categories[i].Title)

This way, the name is the same for all radio buttons. When the form is posted, the 'Selected' property is equal to the category title (or id or whatever) and this can be used to update the binding on the relevant radiobutton, like this...

model.Categories.Find(m => m.Title.Equals(model.Selected)).Selected = true;

May not be the best way, but it does work.

Find element's index in pandas Series

If you use numpy, you can get an array of the indecies that your value is found:

import numpy as np
import pandas as pd
myseries = pd.Series([1,4,0,7,5], index=[0,1,2,3,4])
np.where(myseries == 7)

This returns a one element tuple containing an array of the indecies where 7 is the value in myseries:

(array([3], dtype=int64),)

MySQL selecting yesterday's date

The simplest and best way to get yesterday's date is:

subdate(current_date, 1)

Your query would be:

SELECT 
    url as LINK,
    count(*) as timesExisted,
    sum(DateVisited between UNIX_TIMESTAMP(subdate(current_date, 1)) and
        UNIX_TIMESTAMP(current_date)) as timesVisitedYesterday
FROM mytable
GROUP BY 1

For the curious, the reason that sum(condition) gives you the count of rows that satisfy the condition, which would otherwise require a cumbersome and wordy case statement, is that in mysql boolean values are 1 for true and 0 for false, so summing a condition effectively counts how many times it's true. Using this pattern can neaten up your SQL code.

Incorrect syntax near ''

You can identify the encoding used for the file (in this case sql file) using an editor (I used Visual studio code). Once you open the file, it shows you the encoding of the file at the lower right corner on the editor.

encoding

I had this issue when I was trying to check-in a file that was encoded UTF-BOM (originating from a non-windows machine) that had special characters appended to individual string characters

You can change the encoding of your file as follows:

In the bottom bar of VSCode, you'll see the label UTF-8 With BOM. Click it. A popup opens. Click Save with encoding. You can now pick a new encoding for that file (UTF-8)

Python - Move and overwrite files and folders

You can use this to copy directory overwriting existing files:

import shutil
shutil.copytree("src", "dst", dirs_exist_ok=True)

dirs_exist_ok argument was added in Python 3.8.

See docs: https://docs.python.org/3/library/shutil.html#shutil.copytree

More elegant "ps aux | grep -v grep"

You could use preg_split instead of explode and split on [ ]+ (one or more spaces). But I think in this case you could go with preg_match_all and capturing:

preg_match_all('/[ ]php[ ]+\S+[ ]+(\S+)/', $input, $matches);
$result = $matches[1];

The pattern matches a space, php, more spaces, a string of non-spaces (the path), more spaces, and then captures the next string of non-spaces. The first space is mostly to ensure that you don't match php as part of a user name but really only as a command.

An alternative to capturing is the "keep" feature of PCRE. If you use \K in the pattern, everything before it is discarded in the match:

preg_match_all('/[ ]php[ ]+\S+[ ]+\K\S+/', $input, $matches);
$result = $matches[0];

I would use preg_match(). I do something similar for many of my system management scripts. Here is an example:

$test = "user     12052  0.2  0.1 137184 13056 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust1 cron
user     12054  0.2  0.1 137184 13064 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust3 cron
user     12055  0.6  0.1 137844 14220 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust4 cron
user     12057  0.2  0.1 137184 13052 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust89 cron
user     12058  0.2  0.1 137184 13052 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust435 cron
user     12059  0.3  0.1 135112 13000 ?        Ss   10:00   0:00 php /home/user/public_html/utilities/runProcFile.php cust16 cron
root     12068  0.0  0.0 106088  1164 pts/1    S+   10:00   0:00 sh -c ps aux | grep utilities > /home/user/public_html/logs/dashboard/currentlyPosting.txt
root     12070  0.0  0.0 103240   828 pts/1    R+   10:00   0:00 grep utilities";

$lines = explode("\n", $test);

foreach($lines as $line){
        if(preg_match("/.php[\s+](cust[\d]+)[\s+]cron/i", $line, $matches)){
                print_r($matches);
        }

}

The above prints:

Array
(
    [0] => .php cust1 cron
    [1] => cust1
)
Array
(
    [0] => .php cust3 cron
    [1] => cust3
)
Array
(
    [0] => .php cust4 cron
    [1] => cust4
)
Array
(
    [0] => .php cust89 cron
    [1] => cust89
)
Array
(
    [0] => .php cust435 cron
    [1] => cust435
)
Array
(
    [0] => .php cust16 cron
    [1] => cust16
)

You can set $test to equal the output from exec. the values you are looking for would be in the if statement under the foreach. $matches[1] will have the custx value.

How to check if matching text is found in a string in Lua?

There are 2 options to find matching text; string.match or string.find.

Both of these perform a regex search on the string to find matches.


string.find()

string.find(subject string, pattern string, optional start position, optional plain flag)

Returns the startIndex & endIndex of the substring found.

The plain flag allows for the pattern to be ignored and intead be interpreted as a literal. Rather than (tiger) being interpreted as a regex capture group matching for tiger, it instead looks for (tiger) within a string.

Going the other way, if you want to regex match but still want literal special characters (such as .()[]+- etc.), you can escape them with a percentage; %(tiger%).

You will likely use this in combination with string.sub

Example

str = "This is some text containing the word tiger."
if string.find(str, "tiger") then
  print ("The word tiger was found.")
else
  print ("The word tiger was not found.")
end

string.match()

string.match(s, pattern, optional index)

Returns the capture groups found.

Example

str = "This is some text containing the word tiger."
if string.match(str, "tiger") then
  print ("The word tiger was found.")
else
  print ("The word tiger was not found.")
end

semaphore implementation

Your Fundamentals are wrong, the program won't work, so go through the basics and rewrite the program.

Some of the corrections you must make are:

1) You must make a variable of semaphore type

sem_t semvar;

2) The functions sem_wait(), sem_post() require the semaphore variable but you are passing the semaphore id, which makes no sense.

sem_wait(&semvar);
   //your critical section code
sem_post(&semvar);

3) You are passing the semaphore to sem_wait() and sem_post() without initializing it. You must initialize it to 1 (in your case) before using it, or you will have a deadlock.

ret = semctl( semid, 1, SETVAL, sem);
if (ret == 1)
     perror("Semaphore failed to initialize");

Study the semaphore API's from the man page and go through this example.

How to set <iframe src="..."> without causing `unsafe value` exception?

constructor(
 public sanitizer: DomSanitizer, ) {

 }

I had been struggling for 4 hours. the problem was in img tag. When you use square bracket to 'src' ex: [src]. you can not use this angular expression {{}}. you just give directly from an object example below. if you give angular expression {{}}. you will get interpolation error.

  1. first i used ngFor to iterate the countries

    *ngFor="let country of countries"
    
  2. second you put this in the img tag. this is it.

    <img [src]="sanitizer.bypassSecurityTrustResourceUrl(country.flag)"
    height="20" width="20" alt=""/>
    

what does -zxvf mean in tar -zxvf <filename>?

Instead of wading through the description of all the options, you can jump to 3.4.3 Short Options Cross Reference under the info tar command.

x means --extract. v means --verbose. f means --file. z means --gzip. You can combine one-letter arguments together, and f takes an argument, the filename. There is something you have to watch out for:

Short options' letters may be clumped together, but you are not required to do this (as compared to old options; see below). When short options are clumped as a set, use one (single) dash for them all, e.g., ''tar' -cvf'. Only the last option in such a set is allowed to have an argument(1).


This old way of writing 'tar' options can surprise even experienced users. For example, the two commands:

 tar cfz archive.tar.gz file
 tar -cfz archive.tar.gz file

are quite different. The first example uses 'archive.tar.gz' as the value for option 'f' and recognizes the option 'z'. The second example, however, uses 'z' as the value for option 'f' -- probably not what was intended.

Access to build environment variables from a groovy script in a Jenkins build step (Windows)

One thing to note, if you are using a freestyle job, you won't be able to access build parameters or the Jenkins JVM's environment UNLESS you are using System Groovy Script build steps. I spent hours googling and researching before gathering enough clues to figure that out.

Ruby 'require' error: cannot load such file

Ruby 1.9 has removed the current directory from the load path, and so you will need to do a relative require on this file, as David Grayson says:

require_relative 'tokenizer'

There's no need to suffix it with .rb, as Ruby's smart enough to know that's what you mean anyway.

What is the optimal algorithm for the game 2048?

Many of the other answers use AI with computationally expensive searching of possible futures, heuristics, learning and the such. These are impressive and probably the correct way forward, but I wish to contribute another idea.

Model the sort of strategy that good players of the game use.

For example:

13 14 15 16
12 11 10  9
 5  6  7  8
 4  3  2  1

Read the squares in the order shown above until the next squares value is greater than the current one. This presents the problem of trying to merge another tile of the same value into this square.

To resolve this problem, their are 2 ways to move that aren't left or worse up and examining both possibilities may immediately reveal more problems, this forms a list of dependancies, each problem requiring another problem to be solved first. I think I have this chain or in some cases tree of dependancies internally when deciding my next move, particularly when stuck.


Tile needs merging with neighbour but is too small: Merge another neighbour with this one.

Larger tile in the way: Increase the value of a smaller surrounding tile.

etc...


The whole approach will likely be more complicated than this but not much more complicated. It could be this mechanical in feel lacking scores, weights, neurones and deep searches of possibilities. The tree of possibilities rairly even needs to be big enough to need any branching at all.

SELECT from nothing?

In SQL Server type:

Select 'Your Text'

There is no need for the FROM or WHERE clause.

Webpack "OTS parsing error" loading fonts

In my case adding following lines to lambda.js {my deployed is on AWS Lambda} fixed the issue.

 'font/opentype',
 'font/sfnt',
 'font/ttf',
 'font/woff',
 'font/woff2'

How to access iOS simulator camera

Simulator doesn't have a Camera. If you want to access a camera you need a device. You can't test camera on simulator. You can only check the photo and video gallery.

Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>)

Remove this line from your code:

console.info(JSON.parse(scatterSeries));

Iterating through a variable length array

for(int i = 0; i < array.length; i++)
{
    System.out.println(array[i]);
}

or

for(String value : array)
{
    System.out.println(value);
}

The second version is a "for-each" loop and it works with arrays and Collections. Most loops can be done with the for-each loop because you probably don't care about the actual index. If you do care about the actual index us the first version.

Just for completeness you can do the while loop this way:

int index = 0;

while(index < myArray.length)
{
  final String value;

  value = myArray[index];
  System.out.println(value);
  index++;
}

But you should use a for loop instead of a while loop when you know the size (and even with a variable length array you know the size... it is just different each time).

PHP array delete by value (not key)

To delete multiple values try this one:

while (($key = array_search($del_val, $messages)) !== false) 
{
    unset($messages[$key]);
}

TypeError: unhashable type: 'numpy.ndarray'

numpy.ndarray can contain any type of element, e.g. int, float, string etc. Check the type an do a conversion if neccessary.

Passing in class names to react components

With React's support for string interpolation, you could do the following:

class Pill extends React.Component {
    render() {
       return (
          <button className={`pill ${this.props.styleName}`}>{this.props.children}</button>
       );
    }
}

Pass entire form as data in jQuery Ajax function

You just have to post the data. and Using jquery ajax function set parameters. Here is an example.

<script>
        $(function () {

            $('form').on('submit', function (e) {

                e.preventDefault();

                $.ajax({
                    type: 'post',
                    url: 'your_complete url',
                    data: $('form').serialize(),
                    success: function (response) {
                        //$('form')[0].reset();
                       // $("#feedback").text(response);
                        if(response=="True") {
                            $('form')[0].reset();
                            $("#feedback").text("Your information has been stored.");
                        }
                        else
                            $("#feedback").text(" Some Error has occured Errror !!! ID duplicate");
                    }
                });

            });

        });
    </script>

Is there an easy way to attach source in Eclipse?

Another thought for making that easier when using an automated build:

When you create a jar of one of your projects, also create a source files jar:
project.jar
project-src.jar

Instead of going into the build path options dialog to add a source reference to each jar, try the following: add one source reference through the dialog. Edit your .classpath and using the first jar entry as a template, add the source jar files to each of your other jars.

This way you can use Eclipse's navigation aids to their fullest while still using something more standalone to build your projects.

How to display all methods of an object?

It's not possible with ES3 as the properties have an internal DontEnum attribute which prevents us from enumerating these properties. ES5, on the other hand, provides property descriptors for controlling the enumeration capabilities of properties so user-defined and native properties can use the same interface and enjoy the same capabilities, which includes being able to see non-enumerable properties programmatically.

The getOwnPropertyNames function can be used to enumerate over all properties of the passed in object, including those that are non-enumerable. Then a simple typeof check can be employed to filter out non-functions. Unfortunately, Chrome is the only browser that it works on currently.

?function getAllMethods(object) {
    return Object.getOwnPropertyNames(object).filter(function(property) {
        return typeof object[property] == 'function';
    });
}

console.log(getAllMethods(Math));

logs ["cos", "pow", "log", "tan", "sqrt", "ceil", "asin", "abs", "max", "exp", "atan2", "random", "round", "floor", "acos", "atan", "min", "sin"] in no particular order.

How to set a dropdownlist item as selected in ASP.NET?

You can set the SelectedValue to the value you want to select. If you already have selected item then you should clear the selection otherwise you would get "Cannot have multiple items selected in a DropDownList" error.

dropdownlist.ClearSelection();
dropdownlist.SelectedValue = value;

You can also use ListItemCollection.FindByText or ListItemCollection.FindByValue

dropdownlist.ClearSelection();  
dropdownlist.Items.FindByValue(value).Selected = true;

Use the FindByValue method to search the collection for a ListItem with a Value property that contains value specified by the value parameter. This method performs a case-sensitive and culture-insensitive comparison. This method does not do partial searches or wildcard searches. If an item is not found in the collection using this criteria, null is returned, MSDN.

If you expect that you may be looking for text/value that wont be present in DropDownList ListItem collection then you must check if you get the ListItem object or null from FindByText or FindByValue before you access Selected property. If you try to access Selected when null is returned then you will get NullReferenceException.

ListItem listItem = dropdownlist.Items.FindByValue(value);

if(listItem != null) 
{
   dropdownlist.ClearSelection();
   listItem.Selected = true;
}

RegEx for valid international mobile phone number

// Regex - Check Singapore valid mobile numbers

public static boolean isSingaporeMobileNo(String str) {
    Pattern mobNO = Pattern.compile("^(((0|((\\+)?65([- ])?))|((\\((\\+)?65\\)([- ])?)))?[8-9]\\d{7})?$");
    Matcher matcher = mobNO.matcher(str);
    if (matcher.find()) {
        return true;
    } else {
        return false;
    }
}

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

The regex provided should match any url of the form http://www.ietf.org/rfc/rfc3986.txt; and does when tested in the python interpreter.

What format have the URLs you've been having trouble parsing had?

How to format time since xxx e.g. “4 minutes ago” similar to Stack Exchange sites

Here's what I did (the object returns the unit of time along with its value):

_x000D_
_x000D_
function timeSince(post_date, reference)_x000D_
{_x000D_
 var reference = reference ? new Date(reference) : new Date(),_x000D_
  diff = reference - new Date(post_date + ' GMT-0000'),_x000D_
  date = new Date(diff),_x000D_
  object = { unit: null, value: null };_x000D_
 _x000D_
 if (diff < 86400000)_x000D_
 {_x000D_
  var secs  = date.getSeconds(),_x000D_
   mins  = date.getMinutes(),_x000D_
   hours = date.getHours(),_x000D_
   array = [ ['second', secs], ['minute', mins], ['hour', hours] ];_x000D_
 }_x000D_
 else_x000D_
 {_x000D_
  var days   = date.getDate(),_x000D_
   weeks  = Math.floor(days / 7),_x000D_
   months = date.getMonth(),_x000D_
   years  = date.getFullYear() - 1970,_x000D_
   array  = [ ['day', days], ['week', weeks], ['month', months], ['year', years] ];_x000D_
 }_x000D_
_x000D_
 for (var i = 0; i < array.length; i++)_x000D_
 {_x000D_
  array[i][0] += array[i][1] != 1 ? 's' : '';_x000D_
_x000D_
  object.unit  = array[i][1] >= 1 ? array[i][0] : object.unit;_x000D_
  object.value = array[i][1] >= 1 ? array[i][1] : object.value;_x000D_
 }_x000D_
_x000D_
 return object;_x000D_
}
_x000D_
_x000D_
_x000D_