php常用模块代码

<?php
// 打开文件
$file = fopen("example.txt", "r");

// 检查文件是否成功打开
if ($file) {
    // 读取文件内容
    $content = fread($file, filesize("example.txt"));
    echo $content;
    // 关闭文件
    fclose($file);
} else {
    echo "无法打开文件";
}
?>

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

// 执行查询
$sql = "SELECT id, firstname, lastname FROM MyGuests";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // 输出数据
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
    }
} else {
    echo "0 结果";
}
$conn->close();
?>

<?php
// 启动会话
session_start();

// 设置会话变量
$_SESSION['username'] = "JohnDoe";

// 获取会话变量
echo "用户名: " . $_SESSION['username'];

// 销毁会话
session_destroy();
?>

<?php
require 'vendor/autoload.php';
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

$mail = new PHPMailer(true);

try {
    // 邮件服务器设置
    $mail->isSMTP();
    $mail->Host = 'smtp.example.com';
    $mail->SMTPAuth = true;
    $mail->Username = 'user@example.com';
    $mail->Password = 'password';
    $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
    $mail->Port = 587;

    // 发件人
    $mail->setFrom('from@example.com', 'Mailer');

    // 收件人
    $mail->addAddress('to@example.com', 'Receiver');

    // 邮件内容
    $mail->isHTML(true);
    $mail->Subject = '这里是邮件主题';
    $mail->Body    = '邮件正文内容';

    // 发送邮件
    $mail->send();
    echo '邮件发送成功';
} catch (Exception $e) {
    echo "邮件发送失败: {$mail->ErrorInfo}";
}
?>

<?php
$data = "Hello, World!";

// 生成密钥
$key = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-cbc'));

// 加密数据
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-c6'));
$encrypted = openssl_encrypt($data, 'aes-256-cbc', $key, 0, $iv);

echo "加密数据: " . $encrypted . "\n";

// 解密数据
$decrypted = openssl_decrypt($encrypted, 'aes-256-cbc', $key, 0, $iv);

echo "解密数据: " . $decrypted . "\n";
?>