参数过滤

/**
* 参数过滤
* @param string/array $str
* @return string/array
*/
function get_field($str){
　　if(empty($str)){return;}
　　$string = preg_replace(‘/select | insert | update | and | in | on | left | joins | delete | \% | \= | \/\* | \* | \.\.\/ | \.\/ | union | from | where | group | into | load_file | outfile /‘,‘‘,$str);
　　$new_str = htmlspecialchars($string, ENT_COMPAT);
　　$return = strip_tags(str_replace(PHP_EOL.PHP_EOL, PHP_EOL,$new_str));
　　return $return;
}

$str = ‘select * from table where id = 1 or name " ‘;
echo red_field($str);
输出：*tableid1 or name "