How to change the avatar on the site?

Question

PHP

Hello everyone! Need help! Can you point my finger at which site I can find the code? I'm just a newbie in this area and I want to change the avatar in my profile.

<?php 
session_start();
 if (!$_SESSION['user']) {
    header('Location: index.php');
     # code...
 }

 ?>
 <title>Профиль | PortaleModeSA</title>
<link rel="stylesheet" type="text/css" href="css/bootstrap.css">
<link rel="stylesheet" href="https://bootstraptema.ru/plugins/2015/bootstrap3/bootstrap.min.css" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" />
<script src="https://bootstraptema.ru/plugins/jquery/jquery-1.11.3.min.js"></script>
<script src="https://bootstraptema.ru/plugins/2015/b-v3-3-6/bootstrap.min.js"></script>


<style>
body{background:url(https://bootstraptema.ru/images/bg/bg-1.png)}

#main {
 background-color: #f2f2f2;
 padding: 20px;
-webkit-border-radius: 4px;
 -moz-border-radius: 4px;
 -ms-border-radius: 4px;
 -o-border-radius: 4px;
 border-radius: 4px;
 border-bottom: 4px solid #ddd;
}
#real-estates-detail #author img {
 -webkit-border-radius: 100%;
 -moz-border-radius: 100%;
 -ms-border-radius: 100%;
 -o-border-radius: 100%;
 border-radius: 100%;
 border: 5px solid #ecf0f1;
 margin-bottom: 10px;
}
#real-estates-detail .sosmed-author i.fa {
 width: 30px;
 height: 30px;
 border: 2px solid #bdc3c7;
 color: #bdc3c7;
 padding-top: 6px;
 margin-top: 10px;
}
.panel-default .panel-heading {
 background-color: #fff;
}
#real-estates-detail .slides li img {
 height: 450px;
}

.rectangle {
    width: 200px;
    height: 100px;
    background: grey;
}
</style>
    <div class="d-flex flex-column flex-md-row align-items-center p-3 px-md-4 mb-3 bg-white border-bottom shadow-sm">
  <h5 class="my-0 mr-md-auto font-weight-normal"><a href="index.php">PortaleModeSA</a></h5>
  <nav class="my-2 my-md-0 mr-md-3">
  </nav>
  <a class="btn btn-outline-primary" href="logout.php">Выход</a>
 </div>
</div>
    </div>
<div class="container">
<div id="main">


 <div class="row" id="real-estates-detail">
 <div class="col-lg-4 col-md-4 col-xs-12">
 <div class="panel panel-default">
 <div class="panel-heading">
 <header class="panel-title">
 <div class="text-center">
 <strong style="color: grey;"><?= $_SESSION['user']['role'] ?></strong>
 </div>
 </header>
 </div>
 <div class="panel-body">
 <div class="text-center" id="author">
 <img style="width: 200px; height: 200px;" src="<?= $_SESSION['user']['avatar'] ?>">
 <h3><?= $_SESSION['user']['name'] ?></h3>
 <p>Всемогущий</p>
 <p class="sosmed-author">
 </p>
 </div>
 </div>
 </div>
 </div>
 <div class="col-lg-8 col-md-8 col-xs-12">
 <div class="panel">
 <div class="panel-body">
 <ul id="myTab" class="nav nav-pills">
<button class="btn btn-lg btn-primary btn-block" style="width:250px;height:40px" type="submit" name="do_signup"><a style="color: white;" href="editprofile.php">Настройки</a></button>
 </ul>
 <div id="myTabContent" class="tab-content">
<hr>
 <div class="tab-pane fade active in" id="detail">
 <h4>Профиль</h4>
 <table class="table table-th-block">
 <tbody>
  <tr><td class="active">ID:</td><td><?= $_SESSION['user']['id'] ?></td></tr>
    <tr><td class="active">Email:</td><td><?= $_SESSION['user']['email'] ?></td></tr>
 <tr><td class="active">Зарегистрирован:</td><td><?= $_SESSION['user']['date'] ?>0</td></tr>
 <tr><td class="active">Страна:</td><td>Россия</td></tr>


 </div>
 </form>
 </div>
 </div>
 </div>
 </div>
 </div>
 </div>
</div>

</div><!-- /.main -->
</div><!-- /.container -->

Answer 1

1. Read how to create forms for .
2. Write a function in PHP (with access by URL, as it fits into the action of the form), which will receive a file and save it .
3. The resulting address (where the picture is saved) is written to the database. Search in a search engine for something in the spirit of " How to write to the database php "
4. Immediately look in the direction of security at least at the level of allowed file extensions.

Answer 2

<img style="width: 200px; height: 200px;" src="<?= $_SESSION['user']['avatar'] ?>">

right here. you need to set the path to the picture