This extension serves for validating and filtering data coming usually from some insecure source such as user input.
The following filters currently exist, be sure to read the Filter Constants section for information that describes the behavior of each constant:
Table 1. Existing filters
| ID | Name | Options | Flags | Description |
|---|---|---|---|---|
| FILTER_VALIDATE_INT | "int" |
min_range,
max_range
| FILTER_FLAG_ALLOW_OCTAL, FILTER_FLAG_ALLOW_HEX | Validates value as integer, optionally from the specified range. |
| FILTER_VALIDATE_BOOLEAN | "boolean" | Returns TRUE for "1", "true", "on" and "yes", FALSE for "0", "false", "off", "no", and "", NULL otherwise. | ||
| FILTER_VALIDATE_FLOAT | "float" |
decimal
| FILTER_FLAG_ALLOW_THOUSAND | Validates value as float. |
| FILTER_VALIDATE_REGEXP | "validate_regexp" |
regexp
|
Validates value against regexp, a
Perl-compatible regular expression.
| |
| FILTER_VALIDATE_URL | "validate_url" | FILTER_FLAG_SCHEME_REQUIRED, FILTER_FLAG_HOST_REQUIRED, FILTER_FLAG_PATH_REQUIRED, FILTER_FLAG_QUERY_REQUIRED | Validates value as URL, optionally with required components. | |
| FILTER_VALIDATE_EMAIL | "validate_email" | Validates value as e-mail. | ||
| FILTER_VALIDATE_IP | "validate_ip" | FILTER_FLAG_IPV4, FILTER_FLAG_IPV6, FILTER_FLAG_NO_PRIV_RANGE, FILTER_FLAG_NO_RES_RANGE | Validates value as IP address, optionally only IPv4 or IPv6 or not from private or reserved ranges. | |
| FILTER_SANITIZE_STRING | "string" | FILTER_FLAG_NO_ENCODE_QUOTES, FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_ENCODE_LOW, FILTER_FLAG_ENCODE_HIGH, FILTER_FLAG_ENCODE_AMP | Strip tags, optionally strip or encode special characters. | |
| FILTER_SANITIZE_STRIPPED | "stripped" | Alias of "string" filter. | ||
| FILTER_SANITIZE_ENCODED | "encoded" | FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_ENCODE_LOW, FILTER_FLAG_ENCODE_HIGH | URL-encode string, optionally strip or encode special characters. | |
| FILTER_SANITIZE_SPECIAL_CHARS | "special_chars" | FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_ENCODE_HIGH | HTML-escape '"<>& and characters with ASCII value less than 32, optionally strip or encode other special characters. | |
| FILTER_UNSAFE_RAW | "unsafe_raw" | FILTER_FLAG_STRIP_LOW, FILTER_FLAG_STRIP_HIGH, FILTER_FLAG_ENCODE_LOW, FILTER_FLAG_ENCODE_HIGH, FILTER_FLAG_ENCODE_AMP | Do nothing, optionally strip or encode special characters. | |
| FILTER_SANITIZE_EMAIL | "email" | Remove all characters except letters, digits and !#$%&'*+-/=?^_`{|}~@.[]. | ||
| FILTER_SANITIZE_URL | "url" | Remove all characters except letters, digits and $-_.+!*'(),{}|\\^~[]`<>#%";/?:@&=. | ||
| FILTER_SANITIZE_NUMBER_INT | "number_int" | Remove all characters except digits and +-. | ||
| FILTER_SANITIZE_NUMBER_FLOAT | "number_float" | FILTER_FLAG_ALLOW_FRACTION, FILTER_FLAG_ALLOW_THOUSAND, FILTER_FLAG_ALLOW_SCIENTIFIC | Remove all characters except digits, +- and optionally .,eE. | |
| FILTER_SANITIZE_MAGIC_QUOTES | "magic_quotes" | Apply addslashes(). | ||
| FILTER_CALLBACK | "callback" | callback function or method | Call user-defined function to filter data. |
No external libraries are needed to build this extension.
The behaviour of these functions is affected by settings in php.ini.
Table 2. Filter Configuration Options
| Name | Default | Changeable | Changelog |
|---|---|---|---|
| filter.default | unsafe_raw | PHP_INI_PERDIR | |
| filter.default_flags | PHP_INI_PERDIR |
Here's a short explanation of the configuration directives.
filter.default
stringFilter all $_GET, $_POST, $_COOKIE and $_REQUEST data by this filter. Original data can be accessed through filter_input().
Accepts the name of the filter you like to use by default. See the existing filter list for the list of the filter names.
filter.default_flags
integerDefault flags
This extension has no resource types defined.
The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
POST variables.
GET variables.
COOKIE variables.
ENV variables.
SERVER variables.
SESSION variables. (not implemented yet)
REQUEST variables. (not implemented yet)
No flags.
Flag used to require scalar as input
Require an array as input.
Always returns an array.
Use NULL instead of FALSE on failure.
ID of "int" filter.
ID of "boolean" filter.
ID of "float" filter.
ID of "validate_regexp" filter.
ID of "validate_url" filter.
ID of "validate_email" filter.
ID of "validate_ip" filter.
ID of default ("string") filter.
ID of "unsafe_raw" filter.
ID of "string" filter.
ID of "stripped" filter.
ID of "encoded" filter.
ID of "special_chars" filter.
ID of "email" filter.
ID of "url" filter.
ID of "number_int" filter.
ID of "number_float" filter.
ID of "magic_quotes" filter.
ID of "callback" filter.
Allow octal notation (0[0-7]+) in "int" filter.
Allow hex notation (0x[0-9a-fA-F]+) in "int" filter.
Strip characters with ASCII value less than 32.
Strip characters with ASCII value greater than 127.
Encode characters with ASCII value less than 32.
Encode characters with ASCII value greater than 127.
Encode &.
Don't encode ' and ".
(No use for now.)
Allow fractional part in "number_float" filter.
Allow thousand separator (,) in "number_float" filter.
Allow scientific notation (e, E) in "number_float" filter.
Require scheme in "validate_url" filter.
Require host in "validate_url" filter.
Require path in "validate_url" filter.
Require query in "validate_url" filter.
Allow only IPv4 address in "validate_ip" filter.
Allow only IPv6 address in "validate_ip" filter.
Deny reserved addresses in "validate_ip" filter.
Deny private addresses in "validate_ip" filter.