Sanitization Filter Flags

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.

FILTER_FLAG_STRIP_LOW (int)

Strip characters with ASCII value less than 32.

FILTER_FLAG_STRIP_HIGH (int)

Strip characters with ASCII value greater than 127.

FILTER_FLAG_STRIP_BACKTICK (int)

Strips backtick (`) characters.

FILTER_FLAG_ENCODE_LOW (int)

Encode characters with ASCII value less than 32.

FILTER_FLAG_ENCODE_HIGH (int)

Encode characters with ASCII value greater than 127.

FILTER_FLAG_ENCODE_AMP (int)

Encode &.

FILTER_FLAG_NO_ENCODE_QUOTES (int)

Single and double quotes (' and ") will not be encoded.

FILTER_FLAG_EMPTY_STRING_NULL (int)

If sanitizing a string results in an empty string, convert the value to null