Reusable PHP Functions for Various Projects

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In PHP projects, frequently needed utility functions can be grouped under categories such as database operations, security, data formatting, performance, and file handling. These functions help speed up development and prevent code repetition.

1. Security Functions

1.1. Protection Against SQL Injection (Data Sanitization)

PHP

function sanitizeInput($data, $db) {
    return htmlspecialchars(strip_tags($db->quote($data)));
}

Usage:

PHP

$username = sanitizeInput($_POST['username'], $pdo);

This function helps prevent SQL Injection attacks.

1.2. Strong Password Hashing

PHP

function hashPassword($password) {
    return password_hash($password, PASSWORD_BCRYPT);
}

Usage:

PHP

$hashedPassword = hashPassword('StrongPassword123');

Verification:

PHP

if (password_verify($password, $hashedPassword)) {
    echo 'Password is correct!';
}

This function uses bcrypt to securely store passwords.

1.3. Secure Random Token Generation

PHP

function generateToken($length = 32) {
    return bin2hex(random_bytes($length));
}

Usage:

PHP

$csrfToken = generateToken();

This function generates a secure random string for CSRF tokens or API keys.

2. Database Functions

2.1. Retrieve All Users

PHP

function getAllUsers($db) {
    $stmt = $db->query('SELECT * FROM users');
    return $stmt->fetchAll(PDO::FETCH_ASSOC);
}

Usage:

PHP

$users = getAllUsers($pdo);
print_r($users);

This function retrieves all users from the database.

2.2. Get User Info by ID

PHP

function getUserById($db, $id) {
    $stmt = $db->prepare('SELECT * FROM users WHERE id = :id');
    $stmt->bindParam(':id', $id, PDO::PARAM_INT);
    $stmt->execute();
    return $stmt->fetch(PDO::FETCH_ASSOC);
}

Usage:

PHP

$user = getUserById($pdo, 1);
print_r($user);

This function retrieves user information by given ID.

3. Data Formatting Functions

3.1. Format Dates

PHP

function formatDate($date, $format = 'd-m-Y H:i') {
    return date($format, strtotime($date));
}

Usage:

PHP

echo formatDate('2024-03-05 15:30:00');

This function makes date formats more readable.

3.2. Truncate Text

PHP

function truncateText($text, $length = 100) {
    return strlen($text) > $length ? substr($text, 0, $length) . '...' : $text;
}

Usage:

PHP

echo truncateText('This is a very long text that needs to be shortened.', 20);

This function shortens long text to a defined length.

4. File and Directory Functions

4.1. Human-Readable File Size

PHP

function formatFileSize($bytes) {
    $sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
    $factor = floor((strlen($bytes) - 1) / 3);
    return sprintf('%.2f %s', $bytes / pow(1024, $factor), $sizes[$factor]);
}

Usage:

PHP

echo formatFileSize(2048000); // 1.95 MB

This function converts file size to a human-readable format.

4.2. List Files in a Directory

PHP

function listFiles($dir) {
    return array_diff(scandir($dir), ['.', '..']);
}

Usage:

PHP

print_r(listFiles('uploads'));

This function lists all files in the given directory.

5. Performance Optimization

5.1. Measure Page Load Time

PHP

function startTimer() {
    global $start_time;
    $start_time = microtime(true);
}
function endTimer() {
    global $start_time;
    return round(microtime(true) - $start_time, 5) . ' seconds';
}

Usage:

PHP

startTimer();
// Your process here
echo 'Page load time: ' . endTimer();

This function measures the execution time of PHP scripts.

5.2. Measure Memory Usage

PHP

function getMemoryUsage() {
    return round(memory_get_usage() / 1024 / 1024, 2) . ' MB';
}

Usage:

PHP

echo getMemoryUsage();

This function measures the memory used by the PHP script.

6. Miscellaneous Utility Functions

6.1. Get Client IP Address

PHP

function getClientIP() {
    return $_SERVER['REMOTE_ADDR'] ?? '0.0.0.0';
}

Usage:

PHP

echo getClientIP();

This function returns the IP address of the client.

6.2. Generate Random Password

PHP

function generatePassword($length = 12) {
    return substr(str_shuffle('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*'), 0, $length);
}

Usage:

PHP