ฟังก์ชั่นตัวกรอง PHP
บทนำตัวกรอง PHP
ตัวกรอง PHP นี้ใช้เพื่อตรวจสอบและกรองข้อมูลที่มาจากแหล่งที่ไม่ปลอดภัย เช่น การป้อนข้อมูลของผู้ใช้
การติดตั้ง
จาก PHP 5.2.0 ฟังก์ชันตัวกรองจะถูกเปิดใช้งานโดยค่าเริ่มต้น ไม่จำเป็นต้องติดตั้งเพื่อใช้ฟังก์ชันเหล่านี้
การกำหนดค่ารันไทม์
ลักษณะการทำงานของฟังก์ชันเหล่านี้ได้รับผลกระทบจากการตั้งค่าใน php.ini:
| Name | Description | Default | Changeable |
|---|---|---|---|
| filter.default | Filter all $_GET, $_POST, $_COOKIE, $_REQUEST and $_SERVER data by this filter. Accepts the name of the filter you like to use by default. See the filter list for the list of the filter names | "unsafe_raw" | PHP_INI_PERDIR |
| filter.default_flags | Default flags to apply when the default filter is set. This is set to FILTER_FLAG_NO_ENCODE_QUOTES by default for backwards compatibility reasons | NULL | PHP_INI_PERDIR |
ฟังก์ชั่นตัวกรอง PHP
| Function | Description |
|---|---|
| filter_has_var() | Checks whether a variable of a specified input type exist |
| filter_id() | Returns the filter ID of a specified filter name |
| filter_input() | Gets an external variable (e.g. from form input) and optionally filters it |
| filter_input_array() | Gets external variables (e.g. from form input) and optionally filters them |
| filter_list() | Returns a list of all supported filter names |
| filter_var() | Filters a variable with a specified filter |
| filter_var_array() | Gets multiple variables and filter them |
PHP ค่าคงที่ตัวกรองที่กำหนดไว้ล่วงหน้า
| Constant | Description |
|---|---|
| INPUT_POST | POST variables |
| INPUT_GET | GET variables |
| INPUT_COOKIE | COOKIE variables |
| INPUT_ENV | ENV variables |
| INPUT_SERVER | SERVER variables |
| FILTER_DEFAULT | Do nothing, optionally strip/encode special characters. Equivalent to FILTER_UNSAFE_RAW |
| FILTER_FLAG_NONE | Allows no flags |
| FILTER_FLAG_ALLOW_OCTAL | Only for inputs that starts with a zero (0) as octal numbers. This only allows the succeeding digits to be 0-7 |
| FILTER_FLAG_ALLOW_HEX | Only for inputs that starts with 0x/0X as hexadecimal numbers. This only allows succeeding characters to be a-fA-F0-9 |
| FILTER_FLAG_STRIP_LOW | Strip characters with ASCII value lower than 32 |
| FILTER_FLAG_STRIP_HIGH | Strip characters with ASCII value greater than 127 |
| FILTER_FLAG_ENCODE_LOW | Encode characters with ASCII value lower than 32 |
| FILTER_FLAG_ENCODE_HIGH | Encode characters with ASCII value greater than 127 |
| FILTER_FLAG_ENCODE_AMP | Encode & |
| FILTER_FLAG_NO_ENCODE_QUOTES | Do not encode ' and " |
| FILTER_FLAG_EMPTY_STRING_NULL | Not in use |
| FILTER_FLAG_ALLOW_FRACTION | Allows a period (.) as a fractional separator in numbers |
| FILTER_FLAG_ALLOW_THOUSAND | Allows a comma (,) as a thousands separator in numbers |
| FILTER_FLAG_ALLOW_SCIENTIFIC | Allows an e or E for scientific notation in numbers |
| FILTER_FLAG_PATH_REQUIRED | The URL must contain a path part |
| FILTER_FLAG_QUERY_REQUIRED | The URL must contain a query string |
| FILTER_FLAG_IPV4 | Allows the IP address to be in IPv4 format |
| FILTER_FLAG_IPV6 | Allows the IP address to be in IPv6 format |
| FILTER_FLAG_NO_RES_RANGE | Fails validation for the reserved IPv4 ranges: 0.0.0.0/8, 169.254.0.0/16, 127.0.0.0/8 and 240.0.0.0/4, and for the reserved IPv6 ranges: ::1/128, ::/128, ::ffff:0:0/96 and fe80::/10 |
| FILTER_FLAG_NO_PRIV_RANGE | Fails validation for the private IPv4 ranges: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16, and for the IPv6 addresses starting with FD or FC |
| FILTER_FLAG_EMAIL_UNICODE | Allows the local part of the email address to contain Unicode characters |
| FILTER_REQUIRE_SCALAR | The value must be a scalar |
| FILTER_REQUIRE_ARRAY | The value must be an array |
| FILTER_FORCE_ARRAY | Treats a scalar value as array with the scalar value as only element |
| FILTER_NULL_ON_FAILURE | Return NULL on failure for unrecognized boolean values |
| FILTER_VALIDATE_BOOLEAN | Validates a boolean |
| FILTER_VALIDATE_EMAIL | Validates value as a valid e-mail address |
| FILTER_VALIDATE_FLOAT | Validates value as float |
| FILTER_VALIDATE_INT | Validates value as integer |
| FILTER_VALIDATE_IP | Validates value as IP address |
| FILTER_VALIDATE_MAC | Validates value as MAC address |
| FILTER_VALIDATE_REGEXP | Validates value against a regular expression |
| FILTER_VALIDATE_URL | Validates value as URL |
| FILTER_SANITIZE_EMAIL | Removes all illegal characters from an e-mail address |
| FILTER_SANITIZE_ENCODED | Removes/Encodes special characters |
| FILTER_SANITIZE_MAGIC_QUOTES | Apply addslashes() |
| FILTER_SANITIZE_NUMBER_FLOAT | Remove all characters, except digits, +- signs, and optionally .,eE |
| FILTER_SANITIZE_NUMBER_INT | Removes all characters except digits and + - signs |
| FILTER_SANITIZE_SPECIAL_CHARS | Removes special characters |
| FILTER_SANITIZE_STRING | Removes tags/special characters from a string |
| FILTER_SANITIZE_STRIPPED | Alias of FILTER_SANITIZE_STRING |
| FILTER_SANITIZE_URL | Removes all illegal character from a URL |
| FILTER_UNSAFE_RAW | Do nothing, optionally strip/encode special characters |
| FILTER_CALLBACK | Call a user-defined function to filter data |