PHP_store_and_search_data_for_start_learning

PHP_store_and_search_data_for_start_learning.php

<?php
// for data add
function add_data($id, $name, $phone)
{
    $data = sprintf('%10d%60s%15s', $id, $name, $phone);
    $file = fopen('db.txt', 'a');
    fwrite($file, $data);
    fclose($file);
}


if (isset($_GET['add-data'])) {
    $id = $_GET['id'] + 0;
    $name = $_GET['name'];
    $phone = $_GET['phone'];
    add_data($id, $name, $phone);

}
?>
<?php
// for data show
function get_data()
{
    $file = fopen('db.txt', 'r');
    $filesize = filesize('db.txt');
    $data = fread($file, $filesize);
    fclose($file);
//    echo $data;
    $ln = strlen($data);
    $students = [];
    for ($i = 0; ; $i++) {
        $start = $i * 85;
        $extra = 85;
        if ($start + $extra > $ln) {
            break;
        }

        $student_info = substr($data, $start, $extra);
        $id = trim(substr($student_info, 0, 10));
        $name = trim(substr($student_info, 10, 60));
        $phone = trim(substr($student_info, 70, 15));
//        echo "<br>id: $id - Name: $name - Phone: $phone";
        $student['name'] = $name;
        $student['id'] = $id+0;
        $student['phone'] = $phone;
        $students[] = $student;

    }
    return $students;
}

function show_data(){
    $students = get_data();
    foreach ($students as $student){
        echo $student['id']. '<br>';
    }

}
function show_data_by_id($id){
//    $flag = 0;
    $students = get_data();
    foreach ($students as $student){
        if ($student['id'] == $id) {
            echo $student['name'] . '<br>';
            return;
        }
    }
//    if ($flag == 0){
    echo "No Data Found at roll $id";
//    }

}

if (isset($_GET['search-data'])){
    $id = $_GET['search-id'];
    show_data_by_id($id);
}else{
    show_data();
}

?>

<form action="" method="GET">
    <input type="number" name="id" placeholder="id">
    <input type="text" name="name" placeholder="name">
    <input type="text" name="phone" placeholder="phone">
    <input type="submit" name="add-data" value="Add">
</form>

<br>
<br>
<br>
<form action="" method="GET">
    <input type="number" name="search-id" placeholder="id">
    <input type="submit" name="search-data" value="search">
</form>