Category: Guidelines

Git Commands: How to Remove Local Git Branches that are Merged or Nonexistent

Over time, your local git branches list can become overwhelming, particularly if you develop on a single branch, generate a pull request, merge it into the main branch, and then remove the remote git branch once it has been merged. After the branch is removed from the remote repository, there is no need to keep it on your local machine.

The following command will delete all local branches that have been merged into the main branch. If your git trunk branch is not named main or you wish to remove all branches that have been merged into a branch other than main, simply modify the two instances of the word main in the command to reflect the name of your branch.

Remove local merged git branches

To remove all the local branches, which are merged into the main branch, navigate to the root of the repository and run the following git commands,

  • Fetch the latest updates from the git repository
git fetch
  • See the list of local branches available in the repository
git branch
  • Delete all local branches that have been merged to main branch 
git branch --merged main | grep -v "^\* main" | xargs -n 1 -r git branch -d

The above steps will remove all the branches from the local computer, which are already merged in main branch.

Remove local noexistent git branches

Similarly, to remove all the branches from the local computer, which are deleted or not exists on the remote repository, navigate to the root of the repository and run the following git commands,

  • Fetch the latest updates from the git repository
git fetch
  • See the list of local branches available in the repository
git branch
  • Delete all local branches that have been merged to main branch 
git branch -vv | grep ': gone]' | grep -v '\*' | awk '{ print $1; }' | xargs -r git branch -D

How to upload file code using Laravel

To upload a file using Laravel, you can follow these steps:

Create a new form in your Laravel view with an input field for the file:

<form method="POST" action="{{ route('file.upload') }}" enctype="multipart/form-data">
    @csrf

    <input type="file" name="file">

    <button type="submit">Upload</button>
</form>

Define a new route in your routes/web.php file that points to a controller method that will handle the file upload:

Route::post('/file/upload', [App\Http\Controllers\FileController::class, 'upload'])->name('file.upload');

Create a new controller method in FileController that will handle the file upload:

public function upload(Request $request)
{
    // Validate the uploaded file
    $request->validate([
        'file' => 'required|file|max:1024', // limit file size to 1 MB
    ]);

    // Store the uploaded file in the storage/app/public directory
    $path = $request->file('file')->store('public');

    // Generate a URL for the uploaded file
    $url = Storage::url($path);

    // Redirect back with a success message
    return back()->with('success', 'File uploaded successfully: ' . $url);
}

In the upload() method, we first validate that the uploaded file meets our requirements (in this case, it must be a file and not exceed 1 MB in size). We then use the store() method on the uploaded file to store it in the storage/app/public directory. This directory is publicly accessible, so we can generate a URL for the file using the url() method on the Storage facade. Finally, we redirect back to the form with a success message that includes the URL of the uploaded file.

You can now test the file upload functionality by navigating to the form and selecting a file to upload. If the file meets the validation requirements, it will be uploaded and a success message will be displayed. You can then access the uploaded file at the generated URL.

The Lexical Structure of JavaScript

To understand the structure of JavaScript, you need to learn the following building blocks of it: Unicode, case sensitivity, semicolons, comments, white space, literals, identifiers, and reserved words.

Unicode

You can use Unicode in JavaScript. So, you can use Emojis as variable names and write identifiers in any language, for example, Japanese or Chinese, with some rules. 

If you want to know whether your Unicode variable is acceptable or not, you can check it at https://mothereff.in/js-variables.

Case sensitivity

JavaScript is case-sensitive like many languages. So, a variable name written in a lower case format is different from the same variable name written in a camel case format.

Semicolons

JavaScript has a very C-like syntax, and you might see lots of code samples that feature semicolons at the end of each line.

Semicolons are not mandatory in JavaScript, and it does not have any problem that does not use them. Many developers, coming from languages that do not have semicolons, also started avoiding using them in JavaScript code.

It goes to personal preference and your programming behavior. If you are using those languages where semicolons are mandatory, you can use the same behavior for your JavaScript code.

Comments

Using comments helps us to understand code and its purpose. Each programming language has its own set of syntax when it comes to writing comments.

You can use two kinds of comments in JavaScript:

Single-line comments: Single-line comments begin with //. It will ignore all the things immediately after // syntax until the end of that line. It is also known as inline comments.

// Single-line comment

Multi-line comments: Multi-line comments begin with /* and end with */. You can write as many lines as you want in between these syntaxes.

/* Multi-line
Comment */

Usually, most developers use /* and */ syntax to writing multi-line block comments as JavaScript does not give any error. But the standard way to use multi-line comments in JavaScript is to use block comments as follows;

  1. Start with /** in a blank line.
  2. End with */ at the end line.
  3. Use * at the beginning of each line between the start and the end.
/**
 * Multi-line comment as
 * block comments
 */

White space

JavaScript does not consider white space meaningful like Python. You can add spaces and line breaks in any fashion.

In practice, you will most likely keep a well-defined style of indentation and adhere to what people commonly use.

Literals

We define as literal a value that is written in the source code, for example, a number, a string, a boolean, or also more advanced constructs, like Object Literals or Array Literals:

Identifiers

An identifier is a sequence of characters to identify a variable, a function, or an object. There are specific rules for identifiers as follows,

  • It should start with a letter (it could be any allowed character like emoji 😄 or Unicode words), the dollar signs $, or an underscore _.
  • It can contain digits.

Reserved words

You cannot use reserved JavaScript words as identifiers. Some of the reserve words are as follows,

break
do
instanceof
typeof
case
else
new
var
catch
finally
return
void
continue
for
switch
while
debugger
function
this
with
default
if
throw
delete
in
try
class
enum
extends
super
const
export
import

These reserved words are JavaScript functions or variables, which are used for different operations using JavaScript.

Solved – error while loading shared libraries: libpangox-1.0.so.0: Anydesk on Ubuntu 22.04 LTS

After successfully upgrading from Ubuntu 20.04 LTS to 22.04 LTS, most of the applications are working perfectly. But, some of the applications behave unusually. Such as, I tried to run the Anydesk application, but it doesn’t launch/start. when I checked the status service, the AnyDesk service was failed and the reason for failing is mentioned in the below error message,

anydesk: error while loading shared libraries: libpangox-1.0.so.0: cannot open shared object file: No such file or directory

libpangox-1.0.so.0 is a library used for text layout and rendering the text. Most of the work on Pango-1.0 was done using the GTK+ widget toolkit as a test platform.

So, I ran the command to install it using the apt as follows,

apt install libpangox-1.0-0

But, it gives me the following error,

Package libpangox-1.0-0 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

So, from that we can understand that, libpangox-1.0.so.0 can’t be installed from apt or apt-get. We need to install it manually.

Use the following steps to install libpangox-1.0.so.0 manually,

Step 1. Download the libpangox-1.0 package

wget http://ftp.us.debian.org/debian/pool/main/p/pangox-compat/libpangox-1.0-0_0.0.2-5.1_amd64.deb

Step2: Install the package using apt

sudo apt install ./libpangox-1.0-0_0.0.2-5.1_amd64.deb

Step3: Restart the AnyDesk service

sudo service anydesk restart

After these steps, if you check the AnyDesk service status, it will show active (running).

What is Middleware and how to create one in Laravel?

It’s best to envision middleware as a series of “layers” for HTTP requests that must pass through before they hit your application. Each layer can examine the request and even reject it entirely.

Middleware provides a convenient mechanism for inspecting and filtering HTTP requests entering your application. It’s best to envision middleware as a series of “layers” for HTTP requests that must pass through before they hit your application. Each layer can examine the request and even reject it entirely.

For example, Laravel includes a middleware that verifies the authenticity of the user of your application. If the user is not authenticated, the middleware will redirect the user to your application’s login screen. However, if the user is authenticated, the middleware will allow the request to proceed further into the application.

To perform different tasks, we can develop many middlewares besides authentication. For example, a logging middleware might log all incoming requests to your application. 

Laravel framework has included many middlewares, including middleware for authentication and CSRF protection. All of these middlewares are located in the app/Http/Middleware directory.

To create a middleware, we can use the following command,

php artisan make:middleware <middleware-name>

For example, if we want to create a middleware for checking transactions, we can run the following command,

php artisan make:middleware CheckTransaction

 After successful execution of the command, a middleware class will be created under the app/Http/Middleware directory.

In this class, we can define methods to check transactions. If the transaction is not completed, we can redirect the user back to the failed transaction page. However, on the successful transactions, we can allow users to proceed to the next page.

<?php
 
namespace App\Http\Middleware;
 
use Closure;
 
class CheckTransaction
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {
        if ($request->input('status') !== 'completed') {
            return redirect('transaction-failed');
        }
 
        return $next($request);
    }
}

As you can see, if the transaction status does not set to “completed”, the middleware will return an HTTP redirect to the client; otherwise, the request will be passed further into the application.

To pass the request deeper into the application (allowing the middleware to “pass”), you should call the $next callback with the $request.