PHP 5.5.16 is released

Filter flags

List of filter flags
ID Used with Description
FILTER_FLAG_STRIP_LOW FILTER_SANITIZE_ENCODED, FILTER_SANITIZE_SPECIAL_CHARS, FILTER_SANITIZE_STRING, FILTER_UNSAFE_RAW Strips characters that has a numerical value <32.
FILTER_FLAG_STRIP_HIGH FILTER_SANITIZE_ENCODED, FILTER_SANITIZE_SPECIAL_CHARS, FILTER_SANITIZE_STRING, FILTER_UNSAFE_RAW Strips characters that has a numerical value >127.
FILTER_FLAG_ALLOW_FRACTION FILTER_SANITIZE_NUMBER_FLOAT Allows a period (.) as a fractional separator in numbers.
FILTER_FLAG_ALLOW_THOUSAND FILTER_SANITIZE_NUMBER_FLOAT, FILTER_VALIDATE_FLOAT Allows a comma (,) as a thousands separator in numbers.
FILTER_FLAG_ALLOW_SCIENTIFIC FILTER_SANITIZE_NUMBER_FLOAT Allows an e or E for scientific notation in numbers.
FILTER_FLAG_NO_ENCODE_QUOTES FILTER_SANITIZE_STRING If this flag is present, single (') and double (") quotes will not be encoded.
FILTER_FLAG_ENCODE_LOW FILTER_SANITIZE_ENCODED, FILTER_SANITIZE_STRING, FILTER_SANITIZE_RAW Encodes all characters with a numerical value <32.
FILTER_FLAG_ENCODE_HIGH FILTER_SANITIZE_ENCODED, FILTER_SANITIZE_SPECIAL_CHARS, FILTER_SANITIZE_STRING, FILTER_SANITIZE_RAW Encodes all characters with a numerical value >127.
FILTER_FLAG_ENCODE_AMP FILTER_SANITIZE_STRING, FILTER_SANITIZE_RAW Encodes ampersands (&).
FILTER_NULL_ON_FAILURE FILTER_VALIDATE_BOOLEAN Returns NULL for unrecognized boolean values.
FILTER_FLAG_ALLOW_OCTAL FILTER_VALIDATE_INT Regards inputs starting with a zero (0) as octal numbers. This only allows the succeeding digits to be 0-7.
FILTER_FLAG_ALLOW_HEX FILTER_VALIDATE_INT Regards inputs starting with 0x or 0X as hexadecimal numbers. This only allows succeeding characters to be a-fA-F0-9.
FILTER_FLAG_IPV4 FILTER_VALIDATE_IP Allows the IP address to be in IPv4 format.
FILTER_FLAG_IPV6 FILTER_VALIDATE_IP Allows the IP address to be in IPv6 format.
FILTER_FLAG_NO_PRIV_RANGE FILTER_VALIDATE_IP

Fails validation for the following private IPv4 ranges: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16.

Fails validation for the IPv6 addresses starting with FD or FC.

FILTER_FLAG_NO_RES_RANGE FILTER_VALIDATE_IP Fails validation for the following reserved IPv4 ranges: 0.0.0.0/8, 169.254.0.0/16, 192.0.2.0/24 and 224.0.0.0/4. This flag does not apply to IPv6 addresses.
FILTER_FLAG_PATH_REQUIRED FILTER_VALIDATE_URL Requires the URL to contain a path part.
FILTER_FLAG_QUERY_REQUIRED FILTER_VALIDATE_URL Requires the URL to contain a query string.

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User Contributed Notes 2 notes

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php dot net at ewood dot users dot cementhorizon dot com
3 years ago
In order to filter on loopback addresses try this :

<?php
function FILTER_FLAG_NO_LOOPBACK_RANGE($value) {
   
// Fails validation for the following loopback IPv4 range: 127.0.0.0/8
    // This flag does not apply to IPv6 addresses
   
return filter_var($value, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) ? $value :
        (((
ip2long($value) & 0xff000000) == 0x7f000000) ? FALSE : $value);
}

$var = filter_var('127.0.0.1', FILTER_CALLBACK, array('options' => 'FILTER_FLAG_NO_LOOPBACK_RANGE'));
// Returns FALSE

$var = filter_var('74.125.19.103', FILTER_CALLBACK, array('options' => 'FILTER_FLAG_NO_LOOPBACK_RANGE'));
// Returns '74.125.19.103'

// To filter Private IP ranges and Loopback ranges
$var = filter_var('127.0.0.1', FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE)
    &&
filter_var('127.0.0.1', FILTER_CALLBACK, array('options' => 'FILTER_FLAG_NO_LOOPBACK_RANGE'));
// Returns FALSE
?>

(If someone wants to write in handling for the IPv6 loopback interface at "::1" go for it.)

-Gene Wood
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bohwaz
2 years ago
Please note that FILTER_FLAG_HOST_REQUIRED and FILTER_FLAG_SCHEME_REQUIRED have disappeared. They were previously mentioned in the constants page but it seems that host and scheme are now required by default for the validate_url filter.
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