PHP如何验证一个有效的URL_PHP URL格式合法性验证方法

filter_var()

FILTER_VALIDATE_URL

filter_var()

<?php

function isValidUrl(string $url): bool
{
    // 使用 FILTER_VALIDATE_URL 过滤器来验证URL
    // 这个过滤器会检查URL是否包含有效的协议（如http, https, ftp等），
    // 以及是否具有一个合法的域名或IP地址结构。
    return filter_var($url, FILTER_VALIDATE_URL) !== false;
}

// 示例用法：
$url1 = "http://www.example.com";
$url2 = "https://sub.domain.co.uk/path/to/page?id=123&name=test#section";
$url3 = "ftp://user:pass@ftp.example.com/file.txt";
$url4 = "invalid-url";
$url5 = "http://localhost:8080/api";
$url6 = "http://192.168.1.1/admin";
$url7 = "www.example.com"; // 缺少协议，默认filter_var会认为不合法

echo "URL: '{$url1}' is " . (isValidUrl($url1) ? "valid" : "invalid") . "\n";
echo "URL: '{$url2}' is " . (isValidUrl($url2) ? "valid" : "invalid") . "\n";
echo "URL: '{$url3}' is " . (isValidUrl($url3) ? "valid" : "invalid") . "\n";
echo "URL: '{$url4}' is " . (isValidUrl($url4) ? "valid" : "invalid") . "\n";
echo "URL: '{$url5}' is " . (isValidUrl($url5) ? "valid" : "invalid") . "\n";
echo "URL: '{$url6}' is " . (isValidUrl($url6) ? "valid" : "invalid") . "\n";
echo "URL: '{$url7}' is " . (isValidUrl($url7) ? "valid" : "invalid") . "\n";

?>

filter_var()

false

false

filter_var()

filter_var()

filter_var()

|

<?php

function isValidHttpOrHttpsUrl(string $url): bool
{
    // 要求必须有协议和主机，并且验证通过
    if (!filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_SCHEME_REQUIRED | FILTER_FLAG_HOST_REQUIRED)) {
        return false;
    }

    // 进一步检查协议是否为 http 或 https
    $scheme = parse_url($url, PHP_URL_SCHEME);
    return in_array($scheme, ['http', 'https'], true);
}

$url8 = "www.example.com/test"; // 缺少协议
$url9 = "ftp://example.com";    // 非http/https协议
$url10 = "https://example.com/path";

echo "URL: '{$url8}' (HTTP/HTTPS required) is " . (isValidHttpOrHttpsUrl($url8) ? "valid" : "invalid") . "\n";
echo "URL: '{$url9}' (HTTP/HTTPS required) is " . (isValidHttpOrHttpsUrl($url9) ? "valid" : "invalid") . "\n";
echo "URL: '{$url10}' (HTTP/HTTPS required) is " . (isValidHttpOrHttpsUrl($url10) ? "valid" : "invalid") . "\n";

?>

filter_var()

filter_var()

parse_url()

parse_url()

filter_var()

<?php
$url = "https://user:pass@www.example.com:8080/path/to/page?id=123&name=test#section";

if (filter_var($url, FILTER_VALIDATE_URL)) {
    $parts = parse_url($url);

    echo "Scheme: " . ($parts['scheme'] ?? 'N/A') . "\n";
    echo "Host: " . ($parts['host'] ?? 'N/A') . "\n";
    echo "Path: " . ($parts['path'] ?? 'N/A') . "\n";
    echo "Query: " . ($parts['query'] ?? 'N/A') . "\n";

    // 业务逻辑：只允许特定主机或协议
    if (isset($parts['host']) && $parts['host'] !== 'www.example.com') {
        echo "Error: Host not allowed.\n";
    }
    if (isset($parts['scheme']) && !in_array($parts['scheme'], ['http', 'https'])) {
        echo "Error: Only HTTP/HTTPS schemes are allowed.\n";
    }
} else {
    echo "URL is not syntactically valid.\n";
}
?>

parse_url()

http

https

filter_var()

<?php
// 示例：验证一个字符串是否是形如 "example.com" 或 "sub.example.org" 的域名（不含协议）
function isValidDomainOnly(string $domain): bool
{
    // 这个正则只是一个非常简化的示例，不适用于所有域名规则
    // 真实的域名验证要复杂得多
    return preg_match('/^[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*\.[a-zA-Z]{2,6}$/', $domain);
}

echo "'example.com' is " . (isValidDomainOnly("example.com") ? "valid" : "invalid") . "\n";
echo "'sub.domain.org' is " . (isValidDomainOnly("sub.domain.org") ? "valid" : "invalid") . "\n";
echo "'http://example.com' is " . (isValidDomainOnly("http://example.com") ? "valid" : "invalid") . "\n"; // 预期为invalid
?>

filter_var()

parse_url()

filter_var()

parse_url()