php filter函数库 (与变量和类型有关的扩展)，可以过滤常用邮件,IP,变量数组等

filter扩展库简介

This extension filters data by either validating or sanitizing it. This is especially useful when the data source contains unknown (or foreign) data, like user supplied input. For example, this data may come from an HTML form.

There are two main types of filtering: validation and sanitization.

Validation is used to validate or check if the data meets certain qualifications. For example, passing in FILTER_VALIDATE_EMAIL will determine if the data is a valid email address, but will not change the data itself.

Sanitization will sanitize the data, so it may alter it by removing undesired characters. For example, passing in FILTER_SANITIZE_EMAIL will remove characters that are inappropriate for an email address to contain. That said, it does not validate the data.

Flags are optionally used with both validation and sanitization to tweak behaviour according to need. For example, passing in FILTER_FLAG_PATH_REQUIRED while filtering an URL will require a path (like /foo in http://example.org/foo) to be present.

这个扩展过滤器数据通过验证和消毒。这是特别有用,当数据源包含未知(或外国)数据,比如用户提供的输入。例如,这个数据可能来自一个HTML表单。　　有两种主要类型的过滤:验证和数据消毒。　　验证是用于验证或检查数据满足一定的条件。例如,通过在滤波器验证电子邮件将决定如果数据是一个有效的电子邮件地址,但不会改变数据本身。　　将清洁卫生处理的数据,所以它可能改变它通过消除不受欢迎的人物。例如,通过在过滤净化电子邮件将删除字符不含有一个电子邮件地址。据说,它不验证数据。　　旗帜是选择性地用于验证和数据消毒根据需要来调整行为。例如,passin

过滤的函数列表：

函数名功能

filter_list 过滤器列表――返回一个列表的所有支持的过滤器

filter_id 过滤器ID -返回过滤器ID属于一个名叫过滤器

filter_has_var 过滤器已经var -检查如果变量指定类型的存在

filter_input 过滤输入――得到一个特定的外部变量的名称,并选择性地过滤它

filter_input_array 过滤输入数组――得到外部变量和选择性地过滤它们

filter_var 使用filter_var过滤变量指定的过滤器

filter_var_array 过滤器var数组――得到多个变量和选择性地过滤它们

函数示例：

filter_list

<?php
print_r(filter_list());
?> 

以上例程的输出类似于：

Array
(
    [0] => int
    [1] => boolean
    [2] => float
    [3] => validate_regexp
    [4] => validate_url
    [5] => validate_email
    [6] => validate_ip
    [7] => string
    [8] => stripped
    [9] => encoded
    [10] => special_chars
    [11] => unsafe_raw
    [12] => email
    [13] => url
    [14] => number_int
    [15] => number_float
    [16] => magic_quotes
    [17] => callback
)

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?filter_list和filter_id结合

<?php
echo "<pre class="brush:php;toolbar:false">";
print_r(filter_list());
echo "

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"; foreach (filter_list() as $key => $value) { echo "
".$key."=".$value.'='.filter_id($value); } ?> 0=int=257 1=boolean=258 2=float=259 3=validate_regexp=272 4=validate_url=273 5=validate_email=274 6=validate_ip=275 7=string=513 8=stripped=513 9=encoded=514 10=special_chars=515 11=unsafe_raw=516 12=email=517 13=url=518 14=number_int=519 15=number_float=520 16=magic_quotes=521 17=callback=1024

?filter_id

<?php 
$filters = filter_list(); 
foreach($filters as $filter_name) { 
    echo $filter_name .": ".filter_id($filter_name) ."<br>"; 
} 
?> 
Will result in: 
boolean: 258 
float: 259 
validate_regexp: 272 
validate_url: 273 
validate_email: 274 
validate_ip: 275 
string: 513 
stripped: 513 
encoded: 514 
special_chars: 515 
unsafe_raw: 516 
email: 517 
url: 518 
number_int: 519 
number_float: 520 
magic_quotes: 521 
callback: 1024

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filter_has_var 函数效率：

To note: filter_has_var() is a bit faster than isset()

翻译：filter_has_var函数比isset()快一点

Please note that the function does not check the live array, it actually checks the content received by php:

翻译：请注意，这个函数不检查包括数组，它只检查PHP接收到的内容

<?php
$_GET['test'] = 1;
echo filter_has_var(INPUT_GET, 'test') ? 'Yes' : 'No';
?>

would say "No", unless the parameter was actually in the querystring.

Also, if the input var is empty, it will say Yes.

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验证范例1（验证邮箱）：

<?php
$email_a = 'joe@example.com';
$email_b = 'bogus';

if (filter_var($email_a, FILTER_VALIDATE_EMAIL)) {
    echo "This (email_a) email address is considered valid.";
}
if (filter_var($email_b, FILTER_VALIDATE_EMAIL)) {
    echo "This (email_b) email address is considered valid.";
}
?>

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?以上程序输出：

This (email_a) email address is considered valid.

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验证范例2（验证IP）

<?php
$ip_a = '127.0.0.1';
$ip_b = '42.42';

if (filter_var($ip_a, FILTER_VALIDATE_IP)) {
    echo "This (ip_a) IP address is considered valid.";
}
if (filter_var($ip_b, FILTER_VALIDATE_IP)) {
    echo "This (ip_b) IP address is considered valid.";
}
?>

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?以上程序输出：

This (ip_a) IP address is considered valid.

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验证范例3（通过选项来过滤变量）：

<?php
$int_a = '1';
$int_b = '-1';
$int_c = '4';
$options = array(
    'options' => array(
                      'min_range' => 0,
                      'max_range' => 3,
                      )
);
if (filter_var($int_a, FILTER_VALIDATE_INT, $options) !== FALSE) {
    echo "This (int_a) integer is considered valid (between 0 and 3).\n";
}
if (filter_var($int_b, FILTER_VALIDATE_INT, $options) !== FALSE) {
    echo "This (int_b) integer is considered valid (between 0 and 3).\n";
}
if (filter_var($int_c, FILTER_VALIDATE_INT, $options) !== FALSE) {
    echo "This (int_c) integer is considered valid (between 0 and 3).\n";
}

$options['options']['default'] = 1;
if (($int_c = filter_var($int_c, FILTER_VALIDATE_INT, $options)) !== FALSE) {
    echo "This (int_c) integer is considered valid (between 0 and 3) and is $int_c.";
}
?>

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?以上程序会输出：

This (int_a) integer is considered valid (between 0 and 3).
This (int_c) integer is considered valid (between 0 and 3) and is 1.

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消失有害字符并且验证示例1：

<?php
$a = 'joe@example.org';
$b = 'bogus - at - example dot org';
$c = '(bogus@example.org)';

$sanitized_a = filter_var($a, FILTER_SANITIZE_EMAIL);
if (filter_var($sanitized_a, FILTER_VALIDATE_EMAIL)) {
    echo "This (a) sanitized email address is considered valid.\n";
}

$sanitized_b = filter_var($b, FILTER_SANITIZE_EMAIL);
if (filter_var($sanitized_b, FILTER_VALIDATE_EMAIL)) {
    echo "This sanitized email address is considered valid.";
} else {
    echo "This (b) sanitized email address is considered invalid.\n";
}

$sanitized_c = filter_var($c, FILTER_SANITIZE_EMAIL);
if (filter_var($sanitized_c, FILTER_VALIDATE_EMAIL)) {
    echo "This (c) sanitized email address is considered valid.\n";
    echo "Before: $c\n";
    echo "After:  $sanitized_c\n";    
}
?>

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?以上程序会输出：

This (a) sanitized email address is considered valid.
This (b) sanitized email address is considered invalid.
This (c) sanitized email address is considered valid.
Before: (bogus@example.org)
After: bogus@example.org

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下面介绍一下filter_input，摘自百度百科：

定义和用法

filter_input() 函数从脚本外部获取输入，并进行过滤。

　　本函数用于对来自非安全来源的变量进行验证，比如用户的输入。

　　本函数可从各种来源获取输入：

　　INPUT_GET

　　INPUT_POST

　　INPUT_COOKIE

　　INPUT_ENV

　　INPUT_SERVER

　　INPUT_SESSION (Not yet implemented)

　　INPUT_REQUEST (Not yet implemented)

　　如果成功，则返回被过滤的数据，如果失败，则返回 false，如果?variable?参数未设置，则返回 NULL。

语法

　　filter_input(input_type, variable, filter, options)

参数描述

input_type	必需。规定输入类型。参见上面的列表中可能的类型。
variable	规定要过滤的变量。
filter	可选。规定要使用的过滤器的 ID。默认是 FILTER_SANITIZE_STRING。? 请参见完整的 PHP Filter 函数参考手册，获得可能的过滤器。? 过滤器 ID 可以是 ID 名称（比如 FILTER_VALIDATE_EMAIL），或 ID 号（比如 274）。
options	规定包含标志/选项的数组。检查每个过滤器可能的标志和选项。

例子

　　在本例中，我们使用 filter_input() 函数来过滤一个 POST 变量。所接受的 POST 变量是合法的 e-mail 地址。

　　{ echo "E-Mail is not valid"; }
　　else
　　{ echo "E-Mail is valid"; }
　　?>
　　输出类似：
　　E-Mail is valid

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过滤和验证字串的过滤类型详细请见PHP官方手册

写这篇内容的时候发现以前有朋友写过了，给个链接可以查看一下更多?http://blog.johnsonlu.org/phpfilter/

Related labels：

email filter validate

source：php.cn

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