Upload a new file.

upload.php

<?php
// THIS FiLE WAS COPIED FROM w3schools
function upload(): int
{
    $target_dir = "./uploads/";
    $target_file = $target_dir . basename($_FILES["upload"]["name"]);

    $uploadOk = 1;
    $imageFileType = strtolower(pathinfo($target_file, PATHINFO_EXTENSION));
    echo $target_file . "</br>";

    // Check if image file is a actual image or fake image
    if (isset($_POST["submit"])) {
        $check = getimagesize($_FILES["upload"]["tmp_name"]);
        if ($check !== false) {
            echo "File is an image - " . $check["mime"] . ".";
        } else {
            echo "File is not an image.";
            $uploadOk = 0;
        }
    }
// Check if file already exists
//    if (file_exists($target_file)) {
//        echo "Sorry, file already exists.";
//        $uploadOk = 0;
//    }
// Check file size
    if ($_FILES["upload"]["size"] > 50000000) {
        echo "Sorry, your file is too large.";
        $uploadOk = 0;
    }
// Allow certain file formats
    if ($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg"
        && $imageFileType != "gif") {
        echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed.";
        $uploadOk = 0;
    }
    if ($uploadOk == 0) {
        echo "Sorry, your file was not uploaded.";
   } else {
        if (move_uploaded_file($_FILES["upload"]["tmp_name"], $target_file)) {
            echo "The file " . htmlspecialchars(basename($_FILES["upload"]["name"])) . " has been uploaded.";

        } else {
            $uploadOk=0;
            print_r( $_FILES["upload"]);;
            echo "Sorry, there was an error uploading your file.";

        }
    }
    return $uploadOk;
}