# URL
* [base64_decode - 对使用 MIME base64 编码的数据进行解码](#base64decode)
* [base64_encode - 使用 MIME base64 对数据进行编码](#base64encode)
* [get_headers - 取得服务器响应一个 HTTP 请求所发送的所有报头](#getheaders)
* [get_meta_tags - 从一个文件中提取所有的 meta 标签 content 属性，返回一个数组](#getmetatags)
* [http_build_query - 生成 URL-encode 之后的请求字符串](#httpbuildquery)
* [parse_url - 解析 URL ，返回其组成部分](#parseurl)
* [rawurldecode - 对已编码的 URL 字符串进行解码](#rawurldecode)
* [rawurlencode - 按照 RFC 3986 对 URL 进行编码](#rawurlencode)
* [urldecode - 对已编码的 URL 字符串进行解码](#urldecode)
* [urlencode - 编码 URL 字符串](#urlencode)
## base64_decode
```php
```
## http_build_query
```php
'cat', 'bar' => 'dog'])); // string(15) "foo=cat&bar=dog"
var_dump(http_build_query(['foo' => 'cat', 'bar' => ['dog']])); // string(22) "foo=cat&bar%5B0%5D=dog"
var_dump(http_build_query(['foo', 'bar'], 'prefix_')); // string(25) "prefix_0=foo&prefix_1=bar"
var_dump(http_build_query(['foo', 'bar'], 'prefix_', '&')); // string(29) "prefix_0=foo&prefix_1=bar"
var_dump(http_build_query(['foo' => 'cat dog'], 'prefix_', '&', PHP_QUERY_RFC1738)); // string(11) "foo=cat+dog"
var_dump(http_build_query(['foo' => 'cat dog'], 'prefix_', '&', PHP_QUERY_RFC3986)); // string(13) "foo=cat%20dog"
```
## parse_url
```php
string(4) "http" ["host"]=> string(8) "hostname" ["port"]=> int(80) ["user"]=> string(8) "username" ["pass"]=> string(8) "password" ["path"]=> string(5) "/path" ["query"]=> string(9) "arg=value" ["fragment"]=> string(6) "anchor" }
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_SCHEME)); // string(4) "http"
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_HOST)); // string(8) "hostname"
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_PORT)); // int(80)
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_USER)); // string(8) "username"
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_PASS)); // string(8) "password"
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_PATH)); // string(5) "/path"
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_QUERY)); // string(9) "arg=value"
var_dump(parse_url('http://username:password@hostname:80/path?arg=value#anchor', PHP_URL_FRAGMENT)); // string(6) "anchor"
```
## rawurldecode
```php