curl的使用

1、curl介绍（需要开启curl扩展）

curl是PHP的一个扩展，利用该扩展可以实现服务器之间的数据或文件的传输，也就是curl就是一个工具，用来做服务器之间的数据，文件传输的工具。

 2、应用场景

可以用来采集html网页文件，其他服务器提供的接口数据等

3、curl简单使用

<?php
header('content-type: text/html; charset=utf8');
ini_set('display_errors', true);
$curl = curl_init();                                                    //初始化，并保存句柄
curl_setopt($curl, CURLOPT_URL, 'http://www.baidu.com');  //配置选项
curl_exec($curl);   //执行请求
curl_close($curl);  //关闭curl
?>

 进行post请求

<?php
header('content-type: text/html; charset=utf8');
ini_set('display_errors', true);
$curl = curl_init();                                                    //初始化，并保存句柄
curl_setopt($curl, CURLOPT_POST,true);                           　　　　//进行post请求
curl_setopt($curl, CURLOPT_POSTFIELDS, ['txt' => 'are you ok???']);    //进行post传参
curl_setopt($curl, CURLOPT_URL, 'http://localhost/learn/test.php');    //配置选项
curl_exec($curl);   //执行请求
curl_close($curl);  //关闭curl
?>

注意：如果发送的请求的网站是没有https安全协议的情况下，可以执行跳过安全协议较验证，可以用以下两个配置项

<?php
use Curl\Curl;
header('content-type: text/html; charset=utf8');
ini_set('display_errors', true);
require_once('./vendor/autoload.php');
$curl = curl_init();
//跳过验证https安全协议
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);

curl_setopt($curl, CURLOPT_URL, 'https://www.baidu.com');
curl_exec($curl);
curl_close($curl);
?>

4、启用curl比较成熟的扩展插件（具体可参看https://packagist.org/packages/php-curl-class/php-curl-class）

<?php
use Curl\Curl;
header('content-type: text/html; charset=utf8');
ini_set('display_errors', true);
require_once('./vendor/autoload.php');
$curl = new Curl();
//$curl->setOpt(CURLOPT_SSL_VERIFYHOST, false);
//$curl->setOpt(CURLOPT_SSL_VERIFYPEER, false);
$curl->setOpts([CURLOPT_SSL_VERIFYHOST => false, CURLOPT_SSL_VERIFYPEER => false]);
$curl->get('https://www.baidu.com');
if($curl->error) {
    echo 'Error: ' . $curl->errorCode . ': ' . $curl->errorMessage . "\n";
} else {
    echo '<pre>';
    echo $curl->response;
}
?>

 如果需要传递参数

// https://www.example.com/search?q=keyword
$curl = new Curl();
$curl->get('https://www.example.com/search', array(
    'q' => 'keyword',
));

如果需要设置请求头

<?php
use Curl\Curl;
header('content-type: text/html; charset=utf8');
ini_set('display_errors', true);
require_once('./vendor/autoload.php');
$curl = new Curl();
$curl->setOpts([CURLOPT_SSL_VERIFYHOST => false, CURLOPT_SSL_VERIFYPEER => false]);
$curl->setHeader('Token','46c48bec0d282018b9d167eef7711b2c');
$curl->get('http://*********.php');
if($curl->error) {
    echo 'Error: ' . $curl->errorCode . ': ' . $curl->errorMessage . "\n";
} else {
    $arr = json_decode(json_encode($curl->response), true);
    var_dump($arr);
}
?>

其他设置

$curl->setBasicAuthentication('username', 'password');
$curl->setUserAgent('MyUserAgent/0.0.1 (+https://www.example.com/bot.html)');
$curl->setReferrer('https://www.example.com/url?url=https%3A%2F%2Fwww.example.com%2F');
$curl->setHeader('X-Requested-With', 'XMLHttpRequest');
$curl->setCookie('key', 'value');

post请求

$curl = new Curl();
$curl->post('https://www.example.com/login/', array(
    'username' => 'myusername',
    'password' => 'mypassword',
));

put请求

$curl = new Curl();
$curl->put('https://api.example.com/user/', array(
    'first_name' => 'Zach',
    'last_name' => 'Borboa',
));

delete请求

$curl = new Curl();
$curl->delete('https://api.example.com/user/', array(
    'id' => '1234',
));

下载文件

// Case-insensitive access to headers.
$curl = new Curl();
$curl->download('https://www.example.com/image.png', '/tmp/myimage.png');
echo $curl->responseHeaders['Content-Type'] . "\n"; // image/png
echo $curl->responseHeaders['CoNTeNT-TyPE'] . "\n"; // image/png

句柄关闭

// Manual clean up.
$curl->close();

 利用curl进行上传文件

<?php
use Curl\Curl;
header('content-type: text/html; charset=utf8');
ini_set('display_errors', true);
require_once('./vendor/autoload.php');
$curl = new Curl();
$curl->setOpts([CURLOPT_SSL_VERIFYHOST => false, CURLOPT_SSL_VERIFYPEER => false]);
$curl->post('http://localhost/learn/test.php', ['file' => new CURLFile('C:\wamp64\www\learn\file\other.png')]); //也可以用new CURLFile(realpath('./file/other.png'))

if($curl->error) {
　　 echo 'Error: ' . $curl->errorCode . ': ' . $curl->errorMessage . "\n"; 
} else {
　　 $arr = json_decode(json_encode($curl->response), true); var_dump(json_decode($arr, true)); 
} ?>

模拟接收

<?php
header('content-type: text/html; charset=utf8');
class Test {
    public function __construct() {}
    public function file() {
        $file = $_FILES;
        echo json_encode($file);
    }
}
(new Test())->file();
?>