josanangel's questions

I have this command to see the space of my hard disk of my server: fdisk -land I do a grep to filter more the information that interests me (my main HD):

The command looks like this: fdisk -l | grep vda, and to this I put the header of what each number is (the title) : df -h | grep -m1 "" && df -h | grep "/dev/vda1 ", being as follows ->

Ok, once I have the information I need, I have a script to send emails, which works like this:

enviar_email.sh "(destinatario)" "Titutlo" "Cuerpo Mensaje"

So, the recipient and the Title are covered, but the body of the message I want to send the output of the previous command.

What I have tried without success is:

./enviar_email [email protected] "Un Asunto" $(df -h  | grep  -m1 "" &&  df -h | grep "/dev/vda1 ") 

But the empty mail is sent to others because the command that creates the body fails. What I am trying to do is redirect the output to the style : echo "hola" > hola.txtbut as a parameter to my script.

I don't know if it's because that command doesn't give usable output and if so I don't understand how I could capture it and send it in one step.

And I want to avoid at all costs having to, prior to the script, create a file with the content of the script's output and read it when sending email, I think it's unnecessary.

When I am creating files/directories with my user: jose , the group of these is always docker . It's like I have a mask on or something but there's nothing like this.

I give an example:

1º I create test directory:

▶ mkdir test

2º I look at permissions, users and groups:

▶ ls -ls | grep test
   4 drwxr-xr-x 2 jose docker    4096 ago 31 09:36 test

As you can see docker appears as a group instead of jose . What could this be due to?

I have this in my crontab mysqldumpto make a backup of my bd:

0 5 * * mon,wed,thu,fri root mysqldump test > /var/backups/databases/test_$( date '+%F_%H:%M:%S' ).sql

And I am seeing that no backup of said DB has been made, I have gone to /var/mail/rootand I have found crontab errors that I have received as alerts, specifically:

To: root
Subject: Cron <xxxr> mysqldump   test  > /var/backups/databases/database_test_$( date '+
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-Cron-Env: xxx
X-Cron-Env: xxx
X-Cron-Env: xxx
X-Cron-Env: xxx
Message-Id: xxx
Date: Mon, 12 Apr 2021 03:00:01 +0000 (UTC)

/bin/sh: 1: Syntax error: Unterminated quoted string

Syntax error: Unterminated quoted string

So, because of the error it gives me, I interpret that it doesn't finish reading the line and cuts the script when it goes, data ' +...that's why it gives me a syntax error. But of course, it doesn't make any apparent sense, does it? Why would I cut there?

In fact I have tested the script by hand and it works fine.

Update

I have these environments in the crontab:

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

I am making a bash script to make backup copies of db. Basically I want something like:create_backup.sh {database_name} {table_name}

and run mysqldump database_name.table_name > date.sqlsomething like this.

I want database_nameand to table_namebe optional, that is, if they don't come instead of those vars I will select everything : *.*.

But it doesn't do it right for me, this is my script:

#!/bin/bash

now=$( date '+%F_%H:%M:%S' )

database_name='*'
table_name='*'

if [ -n "$1" ]; then
   $database_name="$1"
fi

if [ -n  "$2" ]; then
   $table_name="$2"
fi

echo "$database_name y $table_name"

echo "mysqldump $database_name.$table_name  > $now.sql"

Clarification: Now I am doing an echo to test that I get what I want.

The script doesn't give me an error, but it doesn't do what it should.

I was making a regExp with the condition of the title: Word that begins and ends in a vowel and both are the same, I have this regExp:

    let re = new RegExp('^[aeiou]*?=$[aeiou]');

The letters between the first and last (if any) do not matter if they are consonants.

It doesn't work, I don't know what I might be missing, this string abcdadoesn't accept it and it should be valid...

I have the following problem:
Given this array of dates in string format:

let arrayStringDate = ["10/01/1995", "20/01/1995", "21/01/2010", "25/01/2010"]

I am trying to parse everything in Datethe following way:

let parsedArray = arrayStringDate.map(date => new Date(date));

The result is that it parses only the first item and the others indicate that they are invalid:

[Sun Oct 01 1995 00:00:00 GMT+0100 (hora estándar de Europa central), Invalid Date, Invalid Date, Invalid Date]<br>

I also tried to do it by going through the array item by item but I get the same result. As you can see, it only parses the first string , the others cause an error. What I can be doing wrong?

I am creating a simple script ( backup_home.sh ) to make backups of a user, I have the following:

#Configuracion del backup home
#--------------------------------
current_date=$(date +%d-%m-%Y)
user='juanito'
dir_backup="/home/.backups/home_${user}"
dir_guardar="/home/${user}"
dir_ignorar="/home/${user}/Documentos/.backups"
nombre_fichero_backup="backup_home_${user}_${current_date}.tar.gz"
####################################################################

echo "------------------------------";
echo "Comienzo del backup de '${dir_guardar}'($(date +%d-%m-%Y))";
echo "------------------------------";

echo "fecha = ${current_date}"
echo "directorio backup = ${dir_backup}"
echo "directorio a guardar = ${dir_guardar}"
echo "directorio a ignorar = ${dir_ignorar}"
echo "nombre fichero backup = ${nombre_fichero_backup}"


tar --exclude=´${dir_ignorar}´ -zcvpf ${dir_guardar} ${dir_backup}



echo "------------------------------";
echo "Fin del backup de '${dir_guardar}'";
echo "------------------------------";

when I run it ( sh backup_home.sh ) it throws me the following error:

tar (child): /home/juanito: No se puede efectuar open: Es un directorio
tar (child): Error is not recoverable: exiting now
/home/.backups/home_juanito/
tar: Child returned status 2
tar: Error is not recoverable: exiting now

I wanted to do a test on my linux server, I wanted each minute to show on the console hola mundo, for this I did the following:

user@server: crontab -e

And after opening it with nano I add to the end of the file:

#prueba task para que haga 'hola mundo' cada minuto
* * * * * echo "hola mundo"

It is supposed that with that, while I am doing things in the linux bash, one should appear hola mundoevery minute, but I stay there waiting more than a minute for the message to come out but nothing comes out .

I am customizing the templates and controllers that Laravel automatically creates for you with the command:

php artisan make:auth

And well, I have it almost finished in a first version of what I want. But I have come across the following problem:
I have added several fields to the table usersthat Laravel creates by default, to customize it, including the img_perfil. The issue of migrations and the addition of new fields to the users table have not caused me any type of problem.
But the issue of the field img_perfildoes hinder me:

When validating it in the frontend part, it is set with a inputtype file:

                <div class="form-group row">
                    <label for="img_perfil" class="col-md-4 col-form-label text-md-right">Imagen de perfil</label>

                    <div class="col-md-6">
                        <input id="img_perfil" type="file" class="form-control @error('img_perfil') is-invalid @enderror" name="img_perfil" value="{{ old('img_perfil') }}" autocomplete="img_perfil">
                        @error('img_perfil')
                            <span class="invalid-feedback" role="alert">
                                <strong>{{ $message }}</strong>
                            </span>
                        @enderror
                    </div>
                </div>

In my backend validation ( fileControllers\Auth\RegisterController.php ) I have it as follows:

<?php

namespace App\Http\Controllers\Auth;

use App\User;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\Hash;
use Illuminate\Support\Facades\Validator;
use Illuminate\Foundation\Auth\RegistersUsers;

class RegisterController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Register Controller
    |--------------------------------------------------------------------------
    |
    | This controller handles the registration of new users as well as their
    | validation and creation. By default this controller uses a trait to
    | provide this functionality without requiring any additional code.
    |
    */

    use RegistersUsers;

    /**
     * Where to redirect users after registration.
     *
     * @var string
     */
    protected $redirectTo = '/home';

    /**
     * Create a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->middleware('guest');
    }

    /**
     * Get a validator for an incoming registration request.
     *
     * @param  array  $data
     * @return \Illuminate\Contracts\Validation\Validator
     */
    protected function validator(array $data)
    {
        return Validator::make($data, [
            'name' => ['required', 'string', 'max:255'],
            'email' => ['required', 'string', 'email', 'max:255', 'unique:users'],
            'password' => ['required', 'string', 'min:8', 'confirmed'],

            'apel_1'=>['string','max:255'],
            'apel_2'=>['string','max:255'],
            'user_name'=>['string','required','max:20','unique:users'],
            'img_perfil'=>['max:100000','mimes:jpg,png,jpeg,gif'],


        ]);
    }

    /**
     * Create a new user instance after a valid registration.
     *
     * @param  array  $data
     * @return \App\User
     */
    protected function create(array $data)
    {
        return User::create([
            'name' => $data['name'],
            'email' => $data['email'],
            'password' => Hash::make($data['password']),

            'apel_1' => $data['apel_1'],
            'apel_2' => $data['apel_2'],
            'user_name' => $data['user_name'],
            'img_perfil' => $data['img_perfil']

        ]);
    }
}

As can be seen, in the validation of the field img_perfilit is set as follows:

'img_perfil'=>['max:100000','mimes:jpg,png,jpeg,gif'],

It is understood that the validation that I do is: image size | extensions allowed I am not indicating that it is required, because when I do a test to insert user without selecting any photo it tells me:

The img profile must be a file of type: jpg, png, jpeg, gif.

But that should tell me if I have selected a photo. If there isn't, then it doesn't validate anything.

I would like to solve a doubt regarding those commitof git

Let's suppose the following example:

I have created a repository on GitHub , let's call it example . In git bash I have linked it to a directory on my pc to start working on that repository. Finally I create 1 branch called main(I would have at this point the main branch and the master branch ). And I start working on main ...

Main at this point has the same as master as it has been created now, and master has nothing. Therefore neither of the two branches have anything.

1st thing I do :

I create a file calledindex.php . I do a git add index.php to add the file and a git commit -m " mi primer commiteo en este branch" to register the commit, finally I upload it with a git push origin main . With this , the file already uploaded has a main branch.index.php

2nd thing I do:

I append to the index.php un <h1> and then commit . Then I add a <p> and then commit . I have added two things but I have not pushed until this point I have 2 commits in the chamber , that is, in local but not in my remote repository.
Now, when I do the push to upload the commits , these commits ...

Question: Will the two commits be uploaded at once? If so, will these commits have the date of the moment I committed or the moment I pushed ?

I would like to clarify an issue regarding Laravel . These are relationships both at the migration/table level ( Foreign Keys ) and at the Model level (ORM Eloquent ).

I propose an example in which I am currently working, very simple. We have 3 tables ( Worlds, Classes, Races .

Cardinality of relations to be taken into account :

1 World has N Classes and on the other hand 1 World has N Races

Having said this, let's move on to the questions :

Let's start with migrations . I am going to put my example based on the previously mentioned tables:

World Migration

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateMundosTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('mundos', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('nombre')->unique();
            $table->string('descripcion');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('mundos');
    }
}

Well, the world table doesn't have a foreign key , so I just create the migration with its fields and that's it. There is no doubt or problem so far. Let
's continue... Class Migration

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateClasesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('clases', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('nombre')->unique();
            $table->string('descripcion');
            $table->timestamps();

            $table->bigInteger('mundo_id');

            $table->foreign('mundo_id')->references('id')->on('mundos');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('clases');
    }
}

Race Migration

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateRazasTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('razas', function (Blueprint $table) {
            $table->bigIncrements('id');
            $table->string('nombre')->unique();
            $table->string('descripcion');
            $table->timestamps();

            $table->bigInteger('mundo_id');

            $table->foreign('mundo_id')->references('id')->on('mundos');

        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('razas');
    }
}

In the last two migrations ( Migration of Class and Migration of Race ) is where the following doubts arise:
I suppose that in terms of migration, the relationships (which in this case is from one to many , is well contemplated, I do not think it is wrong that) but this is just for the migration part . What about Eloquent ( ORM )? That is, each migration corresponds to a model .
I am going to put in this case one of the two models ( Class and Race ) because it is, after all, the same, and the same method will be applied to it, since boththey are of 1-N relationship . Let's put in the example of the Race model :

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Raza extends Model
{
    //
}

If you notice, in the part of the model (ORM eloquent) I do not indicate at any time the relationship between the model, as I am doing it is at the migration level. But for the model, to my understanding as I have it , it doesn't know the relationships between the models. My doubts are:

1) Should the relationships between tables be done both at the migration level ( as I have done ) and at the model level ( in my case I have an empty model )?

2)If the answer is yes , would I have to put something like this on my models? :

 public function comments()
{
    return $this->hasMany('App\Comment');
}

3) Why should it be in a function and what is the meaning of the name?

4) Is it bad to make a relationship at the migration level but not at the model level? I don't understand the need to do it twice(Migration and model)

I want to insert data in my DB, but first I want to check if the field is empty, if it is, I want to replace it; change : ''to null, but it doesn't, it keeps leaving it as an empty string , that is: ''.

This comes from the form:

$fecha_nacimiento= $_POST['fecha_nacimiento'];

So I do the following:

        if (strlen(trim($fecha_nacimiento)) == 0) {
            $fecha_nacimiento = null;   
        }

Doing echoa strlen(trim($fecha_nacimiento))sample 0. But it does not go through the ifone I have put.

I want to do this because I have a variable $sqlwith the insert, and if it goes through the if I put it to null and if not what I receive.

I receive the dates from inputa type : date.

$sql = "INSERT INTO familiares(fecha_nacimiento) VALUES('".$fecha_nacimiento ."');";

The thing is that it gives an error if I insert a string without DATE format in the DB. For what I wanted to control with an if that tells me, if it is ( .length == 0) that I put it in null. But it doesn't.

CLARIFICATION : The error is not that it puts 'NULL'instead of NULLand detects it as a string, but rather that var_dump()it (whether .length == 0or not) always returns ''.

I am trying to implement a notification system on my web page, and for this I am using the following plugin .

The first thing I did was download the plugin, and insert it into my directory: ../static/notificaciones as shown below:

As you can see, the dirfather is WIKI FAMILY .

I changed the name of .zipthe plugin (call it notifications ) so that it would be more comfortable to import it .

Well, to do a test I have created one testing.phpin this directory: WIKI FAMILIA/testing.php , which is as follows:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Testing</title>

    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">

    <link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/themes/smoothness/jquery-ui.css">

    <!-- TOASTR.CSS DEL PLUGIN -->
    <link href="static/notificaciones/toastr.css" rel="stylesheet">
    <script src="static/notificaciones/toastr.js"></script>

</head>
<body>


    <div class="container">
        <div class="row">
            <div class="col-md-12">
                <h1>Testing</h1>
                <button id="miBoton" class="btn btn-info" click>Float message</button>
            </div>
        </div>
    </div>




    <script
                  src="https://code.jquery.com/jquery-3.4.1.js"
                  integrity="sha256-WpOohJOqMqqyKL9FccASB9O0KwACQJpFTUBLTYOVvVU="
                  crossorigin="anonymous"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>

    <script
                  src="https://code.jquery.com/ui/1.12.1/jquery-ui.js"
                  integrity="sha256-T0Vest3yCU7pafRw9r+settMBX6JkKN06dqBnpQ8d30="
                  crossorigin="anonymous"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js"></script>


    <script>
        $("#miBoton").click(function() {

            toastr.warning('Warning');


        });
    </script>

</body>
</html>

I had to do that because it doesn't work for me and I'm trying to see why. In this file testing.php, what I have done has simply been to create a button and make a toaster warning appear when it is pressed in the simplest way possible, since it does not do it for me. I do not know why. Has anyone had a similar problem with this?

I'm making a function of my UserHandler.php class and it's called insert :

public function insertar($usuario){
    echo gettype($usuario);
}

What I wanted to do before doing the insert is to make sure that the object is of type User .

I have been doing the following test:

$uh = new UsuarioHandler();

$var = new Usuario(
  0, "jose", "apellidos", "[email protected]", "password",
  "españa", '1434-04-03', '2000-01-01'
);
$uh->insertar($var);
$uh->insertar($var);

What happen? because the function insert() returns me: object. It's fine, but I want it to return, for example, a string of the name of the type of the class, that is, something like this: "Usuario"to be able to do an if and check if it is equal to the type that should be passed to it. Security issues.

I am making a Conexion.php class where I have the connection, and the UserHandler.php class where I am in charge of doing all the queries that I need related to the user.

connection.php

<?php 

class Conexion {

    private $hostname;
    private $db;
    private $user;
    private $password ;

    private $connection;


    function __construct(){
        $this->hostname = "localhost";
        $this->db = "tb_crud";
        $this->user = "root";
        $this->password= "";
        $this->connection = null;
    }



    public function conectar(){
        if ($this->connection == null) {
            $this->connection = mysqli_connect($this->hostname, $this->user, $this->password);
            mysqli_select_db($this->connection,$this->db);
            return $this->connection;
        }
        else{
            return null;
        }

    }

    public function desconectar(){
        if ($connection != null) {
            $connection = null;
        }
    }

    public function getConnection(){
        return $this->connection;
    }   
}


 ?>

UserHandler.php

<?php 
    include_once 'Conexion.php';

    class UsuarioHandler{

        private $conexion = null;

        public function __construct(){

            $this->conexion = new Conexion();    
        }


        public function mostrarTodos(){
            $this->conexion->conectar();

            if ($this->conexion != null) {

                $result = $this->conexion->prepare("SELECT * FROM usuarios");
                $result->execute();

                var_dump($result);

                return $result;
            }
            else{
                return null;
            }

        }
    }


     $qhu = new UsuarioHandler();

    $qhu->mostrarTodos();



 ?>

If you look at the file UsuarioHandler.php I have this below the class:

$qhu = new UsuarioHandler();

        $qhu->mostrarTodos();

I'm trying to make sure it works but it's throwing me some errors :

Fatal error: Uncaught Error: Call to undefined method Conexion::prepare() in...


Call to undefined method Conexion::prepare() 

I wanted to force this function to be asynchronous, that's why I've given it to him, asyncbut awaithe, who was trying to put it in the return , won't let me.

Where should I put the await?

public async  loginU(usuario:string, password:string){
    return   this._http
    .get<Usuario>(this.URI+"/existU/"+usuario+"/"+password)
    .pipe(
      map(usuario=>{
        return    usuario;
      })
    )
  }

I have this multidimensional array with the name $mensajes:

[0] => Array (
        [id] => 140
        [titulo] => titulo mensaje 1
        [contenido] => contenido mensaje 1
        [createAt] => 2019-04-25 20:27:59
        [creador] => 1
        [url_img] => 5cc1fc2f3462c0.37633589.png
        [etiquetas] => Array (
            [ids] => Array (
                [0] => 90
                [1] => 89
                )
            [nombres] => Array (
                [0] => etiqueta_mensaje_uno
                [1] => comun
                )
            )
        )
    [1] => Array (
        [id] => 141
        [titulo] => titulo mensaje 2
        [contenido] => contenido mensaje 2
        [createAt] => 2019-04-25 20:29:15
        [creador] => 1
        [url_img] => 5cc1fc7ba0c713.37620569.png
        [etiquetas] => Array (
            [ids] => Array (
                [0] => 91
                [1] => 89
                )
            [nombres] => Array (
                [0] => etiqueta_mensaje_dos
                [1] => comun
                )
            )
        )

First out of curiosity I did a var_dump() but I don't get all the data from it, the arrayschildren are shown to me with a few simple points ..., and that and nothing is the same.

array (size=2)
  0 => 
    array (size=7)
      'id' => string '140' (length=3)
      'titulo' => string 'titulo mensaje 1' (length=16)
      'contenido' => string 'contenido mensaje 1' (length=19)
      'createAt' => string '2019-04-25 20:27:59' (length=19)
      'creador' => string '1' (length=1)
      'url_img' => string '5cc1fc2f3462c0.37633589.png' (length=27)
      'etiquetas' => 
        array (size=2)
          'ids' => 
            array (size=2)
              ...
          'nombres' => 
            array (size=2)
              ...
  1 => 
    array (size=7)
      'id' => string '141' (length=3)
      'titulo' => string 'titulo mensaje 2' (length=16)
      'contenido' => string 'contenido mensaje 2' (length=19)
      'createAt' => string '2019-04-25 20:29:15' (length=19)
      'creador' => string '1' (length=1)
      'url_img' => string '5cc1fc7ba0c713.37620569.png' (length=27)
      'etiquetas' => 
        array (size=2)
          'ids' => 
            array (size=2)
              ...
          'nombres' => 
            array (size=2)
              ...

I tried to go through them with one foreach()that would be logical, but apparently it has conflicts when reading the arrays children:

foreach ($mensajes as $key ) {
            echo "<p>" . $key['id'] . "</p>";
            echo "<p>" . $key['titulo'] . "</p>";
            echo "<p>" . $key['contenido'] . "</p>";
            echo "<p>" . $key['createAt'] . "</p>";
            echo "<p>" . $key['creador'] . "</p>";
            echo "<p>" . $key['url_img'] . "</p>";
            foreach ($key['etiquetas'] as $key2 ) {
                echo "<p>" . $key2['ids'] . "</p>";
                echo "<p>" . $key2['nombres'] . "</p>";
            }
            echo "----------------<br>";

    }

What is the optimal way to go through me arraythat is in an associative way of course, without numbers in the indexes but its key

I have this array:

$datos = array(
        'titulo' => $titulo, 
        'contenido' => $contenido, 
        'usuario' => $usuario
    );

And I want to add a new element but not only the value but also a key to be able to identify it, as it is in the array $datos that I have already created.

So I try this:

array_push($datos, 'url_img' =>$fileNameNew);

but basically it tells me that it cannot have a key , but I would be interested in saving it with its key so that I can deal with it later in certain functions

I'm looking at PHP and I'm seeing a function of how to create a connection in PHP I think it's version 7 , correct me if I'm wrong please.

And this is the function that creates the connection :

  function connect(){
        try {

            $connection =  "mysql:host=". $this->host .";dbname=". $this->db; 
            $options = [
                PDO::ATTR_ERRMODE     => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_EMULATE_PREPARES => false,
            ];

            $pdo = new PDO($connection,$this->user,$this->password,$options);

            return $pdo;

        } catch (\Throwable $th) {
            //throw $th;
        }
    }

Let's see the variable $connectionI understand, it simply concatenates the properties of the class to create the connection as usual. But for example the variable $optionsdoes not know what it intends to do. Neither does the variable $pdo.

And I don't know why it is the variable $pdothat is returned in the function.

I hope someone can help me with this question. Sorry if it's not the right way to ask StackOverflow, I know there was a tag for this type of question, but I don't remember it.
All the best.

I'm updating my formway to do it in Angular 7 I've been reading that I need to import app.module.tsthis : import { ReactiveFormsModule } from '@angular/forms';and put it in my imports:

 imports: [
    ReactiveFormsModule
  ],

Then in my view make use of the new form attribute formControlName, an example would look something like this:

 <input type="email" formControlName="email" class="form-control"  name="email">

Of course, for the view attribute to work, I go to my file.component.ts and import :

import { FormBuilder, FormGroup, Validators } from '@angular/forms';

I then inject it via the constructor:

constructor(private ps:PaisesService,private formBuilder: FormBuilder) {
 this.usuario = new Usuario('','','','','','','','default_image.jpg');
 }

My next step is to create, let's say, the configuration of my formnew Angular 7form gives the possibility to decouple the view and do practically everything from it thanks to the following that I show:fichero.component.ts

 //nuevo form (funcion)
  private buildForm(){
    this.formGroup = this.formBuilder.group({
      nombre_real:'',
      apellidos : '',
      email :'',
      nombre_usuario : '',
      password : '',
      repetir_password:'',    
      img_perfil : 'img_perfil',
      pais : '',


    });

With this, I allow my controls ( ) to be bound to the form of my view , replacing it, thus giving it greater independence.inputs[(ngModel)]

And now we just have to put that works inside the ngOnInit()such that like this:

  ngOnInit() {

    this.cargarPaises();
    //nuevo form
    this.buildForm();

  }

Put in situation I go to my problem :

The bindings of this new form ( this.formBuilder.group({})) work great BUT when I try to bind my inputtype Fileit does not let me set a String, this is what I mean:

 private buildForm(){
    this.formGroup = this.formBuilder.group({
      nombre_real:'',
      apellidos : '',
      email :'',
      nombre_usuario : '',
      password : '',
      repetir_password:'', 

     //Este 'img_perfil' es un input de type File, pero no me acepta Objetos File    ni String

      img_perfil : 'img_perfil',
      pais : '',


    });

Finally I ask:

How do I put something by default that admits it to me and makes a minimum of sense by saying that when it is verified I am only interested in knowing if there is or there is not a file uploaded?