filter_var - PHP code example

The php Function Filter_var

PHP supports a wide range of built-in filters to validate and sanitize user input. While sanitization ensures that data is in a proper format, validation also checks whether it meets certain criteria.

The php function filter_var is used to check the given variable against the specified filter. It is useful for checking the validity of various data types such as email, URL, IP address, and numbers. This function is very helpful in preventing security breaches by validating the data.

This function has two required parameters – the variable to be filtered and the type of filter to use. It also takes an optional third parameter to specify additional filter options. The function returns the filtered variable on success and false on failure.

Filter_var is a very useful function but it has some limitations. For instance, it cannot validate non-Latin domain names. However, this can be resolved by using regular expressions instead.

There are many different filters and flags available for the filter_var function in PHP. Some filters are more restrictive than others and have specific requirements for which they should be used. Some of the most common filters include:

filter_var example

$this
            ->addOption('shell', 's', InputOption::VALUE_REQUIRED, 'The shell type ("'.implode('", "', array_keys($this->completionOutputs)).'")')
            ->addOption('input', 'i', InputOption::VALUE_REQUIRED | InputOption::VALUE_IS_ARRAY, 'An array of input tokens (e.g. COMP_WORDS or argv)')
            ->addOption('current', 'c', InputOption::VALUE_REQUIRED, 'The index of the "input" array that the cursor is in (e.g. COMP_CWORD)')
            ->addOption('api-version', 'a', InputOption::VALUE_REQUIRED, 'The API version of the completion script')
            ->addOption('symfony', 'S', InputOption::VALUE_REQUIRED, 'deprecated')
        ;
    }

    protected function initialize(InputInterface $input, OutputInterface $output): void
    {
        $this->isDebug = filter_var(getenv('SYMFONY_COMPLETION_DEBUG'), \FILTER_VALIDATE_BOOL);
    }

    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        try {
            // "symfony" must be kept for compat with the shell scripts generated by Symfony Console 5.4 - 6.1             $version = $input->getOption('symfony') ? '1' : $input->getOption('api-version');
            if ($version && version_compare($version, self::COMPLETION_API_VERSION, '<')) {
                $message = sprintf('Completion script version is not supported ("%s" given, ">=%s" required).', $version, self::COMPLETION_API_VERSION);
                $this->log($message);

    public function __construct(array $adapters, int $defaultLifetime = 0)
    {
        if (!$adapters) {
            throw new InvalidArgumentException('At least one adapter must be specified.');
        }

        foreach ($adapters as $adapter) {
            if (!$adapter instanceof CacheItemPoolInterface) {
                throw new InvalidArgumentException(sprintf('The class "%s" does not implement the "%s" interface.', get_debug_type($adapter), CacheItemPoolInterface::class));
            }
            if (\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true) && $adapter instanceof ApcuAdapter && !filter_var(\ini_get('apc.enable_cli'), \FILTER_VALIDATE_BOOL)) {
                continue; // skip putting APCu in the chain when the backend is disabled             }

            if ($adapter instanceof AdapterInterface) {
                $this->adapters[] = $adapter;
            } else {
                $this->adapters[] = new ProxyAdapter($adapter);
            }
        }
        $this->adapterCount = \count($this->adapters);
        $this->defaultLifetime = $defaultLifetime;

class BasicErrorHandler
{
    public static function register(bool $debug): void
    {
        error_reporting(-1);

        if (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true)) {
            ini_set('display_errors', $debug);
        } elseif (!filter_var(\ini_get('log_errors'), \FILTER_VALIDATE_BOOL) || \ini_get('error_log')) {
            // CLI - display errors only if they're not already logged to STDERR             ini_set('display_errors', 1);
        }

        if (0 <= \ini_get('zend.assertions')) {
            ini_set('zend.assertions', 1);
            ini_set('assert.active', $debug);
            ini_set('assert.exception', 1);
        }

        set_error_handler(new self());
    }

'string' => \FILTER_DEFAULT,
            'int' => \FILTER_VALIDATE_INT,
            'float' => \FILTER_VALIDATE_FLOAT,
            'bool' => \FILTER_VALIDATE_BOOL,
            default => match ($enumType = is_subclass_of($type, \BackedEnum::class) ? (new \ReflectionEnum($type))->getBackingType()->getName() : null) {
                'int' => \FILTER_VALIDATE_INT,
                'string' => \FILTER_DEFAULT,
                default => throw new \LogicException(sprintf('#[MapQueryParameter] cannot be used on controller argument "%s$%s" of type "%s"; one of array, string, int, float, bool or \BackedEnum should be used.', $argument->isVariadic() ? '...' : '', $argument->getName(), $type ?? 'mixed')),
            }
        };

        $value = filter_var($value, $attribute->filter ?? $filter, $options);

        if (null !== $enumType && null !== $value) {
            $enumFrom = static function D$value) use ($type) {
                if (!\is_string($value) && !\is_int($value)) {
                    return null;
                }

                try {
                    return $type::from($value);
                } catch (\ValueError) {
                    return null;
                }

                return $resource;
            }
        );
    }

    private function resolveHost(RequestInterface $request, array $options): UriInterface
    {
        $uri = $request->getUri();

        if (isset($options['force_ip_resolve']) && !\filter_var($uri->getHost(), \FILTER_VALIDATE_IP)) {
            if ('v4' === $options['force_ip_resolve']) {
                $records = \dns_get_record($uri->getHost(), \DNS_A);
                if (false === $records || !isset($records[0]['ip'])) {
                    throw new ConnectException(\sprintf("Could not resolve IPv4 address for host '%s'", $uri->getHost()), $request);
                }

                return $uri->withHost($records[0]['ip']);
            }
            if ('v6' === $options['force_ip_resolve']) {
                $records = \dns_get_record($uri->getHost(), \DNS_AAAA);
                if (false === $records || !isset($records[0]['ipv6'])) {

$amqpOptions['password'] = urldecode($parsedUrl['pass']);
        }

        if (!isset($amqpOptions['queues'])) {
            $amqpOptions['queues'][$exchangeName] = [];
        }

        $exchangeOptions = $amqpOptions['exchange'];
        $queuesOptions = $amqpOptions['queues'];
        unset($amqpOptions['queues'], $amqpOptions['exchange']);
        if (isset($amqpOptions['auto_setup'])) {
            $amqpOptions['auto_setup'] = filter_var($amqpOptions['auto_setup'], \FILTER_VALIDATE_BOOL);
        }

        $queuesOptions = array_map(function D$queueOptions) {
            if (!\is_array($queueOptions)) {
                $queueOptions = [];
            }
            if (\is_array($queueOptions['arguments'] ?? false)) {
                $queueOptions['arguments'] = self::normalizeQueueArguments($queueOptions['arguments']);
            }

            return $queueOptions;
        },

class ApcuAdapterTest extends AdapterTestCase
{
    protected $skippedTests = [
        'testExpiration' => 'Testing expiration slows down the test suite',
        'testHasItemReturnsFalseWhenDeferredItemIsExpired' => 'Testing expiration slows down the test suite',
        'testDefaultLifeTime' => 'Testing expiration slows down the test suite',
    ];

    public function createCachePool(int $defaultLifetime = 0): CacheItemPoolInterface
    {
        if (!\function_exists('apcu_fetch') || !filter_var(\ini_get('apc.enabled'), \FILTER_VALIDATE_BOOL)) {
            $this->markTestSkipped('APCu extension is required.');
        }
        if ('cli' === \PHP_SAPI && !filter_var(\ini_get('apc.enable_cli'), \FILTER_VALIDATE_BOOL)) {
            if ('testWithCliSapi' !== $this->getName()) {
                $this->markTestSkipped('apc.enable_cli=1 is required.');
            }
        }
        if ('\\' === \DIRECTORY_SEPARATOR) {
            $this->markTestSkipped('Fails transiently on Windows.');
        }

            $params['currencyId'],
            $languageIdChain,
            $params['versionId'] ?? Defaults::LIVE_VERSION,
            $params['currencyFactory'],
            $params['considerInheritance'],
            CartPrice::TAX_STATE_GROSS,
            $rounding
        );

        if ($request->headers->has(PlatformRequest::HEADER_SKIP_TRIGGER_FLOW)) {
            $skipTriggerFlow = filter_var($request->headers->get(PlatformRequest::HEADER_SKIP_TRIGGER_FLOW, 'false'), \FILTER_VALIDATE_BOOLEAN);

            if ($skipTriggerFlow) {
                $context->addState(Context::SKIP_TRIGGER_FLOW);
            }
        }

        $request->attributes->set(PlatformRequest::ATTRIBUTE_CONTEXT_OBJECT, $context);
    }

    protected function getScopeRegistry(): RouteScopeRegistry
    {

/** * Provides the ConfigCache factory implementation, falling back to a * default implementation if necessary. */
    private function getConfigCacheFactory(): ConfigCacheFactoryInterface
    {
        return $this->configCacheFactory ??= new ConfigCacheFactory($this->options['debug']);
    }

    private static function getCompiledRoutes(string $path): array
    {
        if ([] === self::$cache && \function_exists('opcache_invalidate') && filter_var(\ini_get('opcache.enable'), \FILTER_VALIDATE_BOOL) && (!\in_array(\PHP_SAPI, ['cli', 'phpdbg'], true) || filter_var(\ini_get('opcache.enable_cli'), \FILTER_VALIDATE_BOOL))) {
            self::$cache = null;
        }

        if (null === self::$cache) {
            return require $path;
        }

        return self::$cache[$path] ??= require $path;
    }
}

        $queryExtraKeys = array_diff(array_keys($query), array_keys(self::DEFAULT_OPTIONS));
        if (0 < \count($queryExtraKeys)) {
            throw new InvalidArgumentException(sprintf('Unknown option found in DSN: [%s]. Allowed options are [%s].', implode(', ', $queryExtraKeys), implode(', ', array_keys(self::DEFAULT_OPTIONS))));
        }

        $options = $query + $options + self::DEFAULT_OPTIONS;
        $configuration = [
            'buffer_size' => (int) $options['buffer_size'],
            'wait_time' => (int) $options['wait_time'],
            'poll_timeout' => $options['poll_timeout'],
            'visibility_timeout' => $options['visibility_timeout'],
            'auto_setup' => filter_var($options['auto_setup'], \FILTER_VALIDATE_BOOL),
            'queue_name' => (string) $options['queue_name'],
        ];

        $clientConfiguration = [
            'region' => $options['region'],
            'accessKeyId' => urldecode($parsedUrl['user'] ?? '') ?: $options['access_key'] ?? self::DEFAULT_OPTIONS['access_key'],
            'accessKeySecret' => urldecode($parsedUrl['pass'] ?? '') ?: $options['secret_key'] ?? self::DEFAULT_OPTIONS['secret_key'],
        ];
        if (null !== $options['session_token']) {
            $clientConfiguration['sessionToken'] = $options['session_token'];
        }

$data = [];
        $typeCastAttributes = (bool) ($context[self::TYPE_CAST_ATTRIBUTES] ?? $this->defaultContext[self::TYPE_CAST_ATTRIBUTES]);

        foreach ($node->attributes as $attr) {
            if (!is_numeric($attr->nodeValue) || !$typeCastAttributes || (isset($attr->nodeValue[1]) && '0' === $attr->nodeValue[0] && '.' !== $attr->nodeValue[1])) {
                $data['@'.$attr->nodeName] = $attr->nodeValue;

                continue;
            }

            if (false !== $val = filter_var($attr->nodeValue, \FILTER_VALIDATE_INT)) {
                $data['@'.$attr->nodeName] = $val;

                continue;
            }

            $data['@'.$attr->nodeName] = (float) $attr->nodeValue;
        }

        return $data;
    }

        }

        if (null !== $metadata) {
            $filesystem->dumpFile($this->getMetaFile(), serialize($metadata));
            try {
                $filesystem->chmod($this->getMetaFile(), $mode, $umask);
            } catch (IOException) {
                // discard chmod failure (some filesystem may not support it)             }
        }

        if (\function_exists('opcache_invalidate') && filter_var(\ini_get('opcache.enable'), \FILTER_VALIDATE_BOOL)) {
            @opcache_invalidate($this->file, true);
        }
    }

    /** * Gets the meta file path. */
    private function getMetaFile(): string
    {
        return $this->file.'.meta';
    }

$this->assertTrue($c->isDebug());
        $this->assertSame('config', $c->getName());
        $this->assertMatchesRegularExpression('~^'.preg_quote($c->getPhpVersion(), '~').'~', \PHP_VERSION);
        $this->assertMatchesRegularExpression('~'.preg_quote((string) $c->getPhpVersionExtra(), '~').'$~', \PHP_VERSION);
        $this->assertSame(\PHP_INT_SIZE * 8, $c->getPhpArchitecture());
        $this->assertSame(class_exists(\Locale::class, false) && \Locale::getDefault() ? \Locale::getDefault() : 'n/a', $c->getPhpIntlLocale());
        $this->assertSame(date_default_timezone_get(), $c->getPhpTimezone());
        $this->assertSame(Kernel::VERSION, $c->getSymfonyVersion());
        $this->assertSame(4 === Kernel::MINOR_VERSION, $c->isSymfonyLts());
        $this->assertNull($c->getToken());
        $this->assertSame(\extension_loaded('xdebug'), $c->hasXDebug());
        $this->assertSame(\extension_loaded('Zend OPcache') && filter_var(\ini_get('opcache.enable'), \FILTER_VALIDATE_BOOL), $c->hasZendOpcache());
        $this->assertSame(\extension_loaded('apcu') && filter_var(\ini_get('apc.enabled'), \FILTER_VALIDATE_BOOL), $c->hasApcu());
        $this->assertSame(sprintf('%s.%s', Kernel::MAJOR_VERSION, Kernel::MINOR_VERSION), $c->getSymfonyMinorVersion());
        $this->assertContains($c->getSymfonyState(), ['eol', 'eom', 'dev', 'stable']);

        $eom = \DateTimeImmutable::createFromFormat('d/m/Y', '01/'.Kernel::END_OF_MAINTENANCE)->format('F Y');
        $eol = \DateTimeImmutable::createFromFormat('d/m/Y', '01/'.Kernel::END_OF_LIFE)->format('F Y');
        $this->assertSame($eom, $c->getSymfonyEom());
        $this->assertSame($eol, $c->getSymfonyEol());
    }

    public function testCollectWithoutKernel()
    {

        $new->reasonPhrase = (string) $reasonPhrase;

        return $new;
    }

    /** * @param mixed $statusCode */
    private function assertStatusCodeIsInteger($statusCode): void
    {
        if (filter_var($statusCode, FILTER_VALIDATE_INT) === false) {
            throw new \InvalidArgumentException('Status code must be an integer value.');
        }
    }

    private function assertStatusCodeRange(int $statusCode): void
    {
        if ($statusCode < 100 || $statusCode >= 600) {
            throw new \InvalidArgumentException('Status code must be an integer value between 1xx and 5xx.');
        }
    }
}

throw new BadRequestException(sprintf('Input value "%s" contains an array, but "FILTER_REQUIRE_ARRAY" or "FILTER_FORCE_ARRAY" flags were not set.', $key));
        }

        if ((\FILTER_CALLBACK & $filter) && !(($options['options'] ?? null) instanceof \Closure)) {
            throw new \InvalidArgumentException(sprintf('A Closure must be passed to "%s()" when FILTER_CALLBACK is used, "%s" given.', __METHOD__, get_debug_type($options['options'] ?? null)));
        }

        $options['flags'] ??= 0;
        $nullOnFailure = $options['flags'] & \FILTER_NULL_ON_FAILURE;
        $options['flags'] |= \FILTER_NULL_ON_FAILURE;

        $value = filter_var($value, $filter, $options);

        if (null !== $value || $nullOnFailure) {
            return $value;
        }

        $method = debug_backtrace(\DEBUG_BACKTRACE_IGNORE_ARGS | \DEBUG_BACKTRACE_PROVIDE_OBJECT, 2)[1];
        $method = ($method['object'] ?? null) === $this ? $method['function'] : 'filter';
        $hint = 'filter' === $method ? 'pass' : 'use method "filter()" with';

        trigger_deprecation('symfony/http-foundation', '6.3', 'Ignoring invalid values when using "%s::%s(\'%s\')" is deprecated and will throw a "%s" in 7.0; '.$hint.' flag "FILTER_NULL_ON_FAILURE" to keep ignoring them.', $this::class, $method, $key, BadRequestException::class);