在PHP中,我在许多PHP项目中都看到了cURL这个词。是什么?它是如何工作的?

参考链接:cURL


当前回答

Php curl函数(POST,GET,DELETE,PUT)

function curl($post = array(), $url, $token = '', $method = "POST", $json = false, $ssl = true){
    $ch = curl_init();  
    curl_setopt($ch, CURLOPT_URL, $url);    
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
    if($method == 'POST'){
        curl_setopt($ch, CURLOPT_POST, 1);
    }
    if($json == true){
        curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array(
            'Content-Type: application/json','Authorization: Bearer '.$token,'Content-Length: ' . strlen($post)));
    }else{
        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post));
        curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/x-www-form-urlencoded'));
    }
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSLVERSION, 6);
    if($ssl == false){
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    }
    // curl_setopt($ch, CURLOPT_HEADER, 0);     
    $r = curl_exec($ch);    
    if (curl_error($ch)) {
        $statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $err = curl_error($ch);
        print_r('Error: ' . $err . ' Status: ' . $statusCode);
        // Add error
        $this->error = $err;
    }
    curl_close($ch);
    return $r;
}

其他回答

Php curl类(GET,POST,文件上传,会话,发送POST JSON,强制自签名SSL/TLS):

<?php
    // Php curl class
    class Curl {

        public $error;

        function __construct() {}

        function Get($url = "http://hostname.x/api.php?q=jabadoo&txt=gin", $forceSsl = false,$cookie = "", $session = true){
            // $url = $url . "?". http_build_query($data);
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_HEADER, false);        
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_TIMEOUT, 60);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            if($session){
                curl_setopt($ch, CURLOPT_COOKIESESSION, true );
                curl_setopt($ch , CURLOPT_COOKIEJAR, 'cookies.txt');
                curl_setopt($ch , CURLOPT_COOKIEFILE, 'cookies.txt');
            }
            if($forceSsl){
                curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
                curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); // 1, 2
            }
            if(!empty($cookie)){            
                curl_setopt($ch, CURLOPT_COOKIE, $cookie); // "token=12345"
            }
            $info = curl_getinfo($ch);
            $res = curl_exec($ch);        
            if (curl_error($ch)) {
                $this->error = curl_error($ch);
                throw new Exception($this->error);
            }else{
                curl_close($ch);
                return $res;
            }        
        }

        function GetArray($url = "http://hostname.x/api.php", $data = array("name" => "Max", "age" => "36"), $forceSsl = false, $cookie = "", $session = true){
            $url = $url . "?". http_build_query($data);
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_HEADER, false);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_TIMEOUT, 60);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            if($session){
                curl_setopt($ch, CURLOPT_COOKIESESSION, true );
                curl_setopt($ch , CURLOPT_COOKIEJAR, 'cookies.txt');
                curl_setopt($ch , CURLOPT_COOKIEFILE, 'cookies.txt');
            }
            if($forceSsl){
                curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
                curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); // 1, 2
            }
            if(!empty($cookie)){
                curl_setopt($ch, CURLOPT_COOKIE, $cookie); // "token=12345"
            }
            $info = curl_getinfo($ch);
            $res = curl_exec($ch);        
            if (curl_error($ch)) {
                $this->error = curl_error($ch);
                throw new Exception($this->error);
            }else{
                curl_close($ch);
                return $res;
            }        
        }

        function PostJson($url = "http://hostname.x/api.php", $data = array("name" => "Max", "age" => "36"), $forceSsl = false, $cookie = "", $session = true){
            $data = json_encode($data);
            $ch = curl_init($url);                                                                      
            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $data);                                                                  
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_TIMEOUT, 60);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            if($session){
                curl_setopt($ch, CURLOPT_COOKIESESSION, true );
                curl_setopt($ch , CURLOPT_COOKIEJAR, 'cookies.txt');
                curl_setopt($ch , CURLOPT_COOKIEFILE, 'cookies.txt');
            }
            if($forceSsl){
                curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
                curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); // 1, 2
            }
            if(!empty($cookie)){
                curl_setopt($ch, CURLOPT_COOKIE, $cookie); // "token=12345"
            }
            curl_setopt($ch, CURLOPT_HTTPHEADER, array(
                'Authorization: Bearer helo29dasd8asd6asnav7ffa',                                                      
                'Content-Type: application/json',                                                                                
                'Content-Length: ' . strlen($data))                                                                       
            );        
            $res = curl_exec($ch);
            if (curl_error($ch)) {
                $this->error = curl_error($ch);
                throw new Exception($this->error);
            }else{
                curl_close($ch);
                return $res;
            } 
        }

        function Post($url = "http://hostname.x/api.php", $data = array("name" => "Max", "age" => "36"), $files = array('ads/ads0.jpg', 'ads/ads1.jpg'), $forceSsl = false, $cookie = "", $session = true){
            foreach ($files as $k => $v) {
                $f = realpath($v);
                if(file_exists($f)){
                    $fc = new CurlFile($f, mime_content_type($f), basename($f)); 
                    $data["file[".$k."]"] = $fc;
                }
            }
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_POST, 1);
            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");        
            curl_setopt($ch, CURLOPT_POSTFIELDS, $data);    
            curl_setopt($ch, CURLOPT_SAFE_UPLOAD, false); // !!!! required as of PHP 5.6.0 for files !!!
            curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2) Gecko/20100115 Firefox/3.6 (.NET CLR 3.5.30729)");
            curl_setopt($ch, CURLOPT_TIMEOUT, 60);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            if($session){
                curl_setopt($ch, CURLOPT_COOKIESESSION, true );
                curl_setopt($ch , CURLOPT_COOKIEJAR, 'cookies.txt');
                curl_setopt($ch , CURLOPT_COOKIEFILE, 'cookies.txt');
            }
            if($forceSsl){
                curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
                curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0); // 1, 2
            }
            if(!empty($cookie)){
                curl_setopt($ch, CURLOPT_COOKIE, $cookie); // "token=12345"
            }
            $res = curl_exec($ch);
            if (curl_error($ch)) {
                $this->error = curl_error($ch);
                throw new Exception($this->error);
            }else{
                curl_close($ch);
                return $res;
            } 
        }
    }
?>

例子:

<?php
    $urlget = "http://hostname.x/api.php?id=123&user=bax";
    $url = "http://hostname.x/api.php";
    $data = array("name" => "Max", "age" => "36");
    $files = array('ads/ads0.jpg', 'ads/ads1.jpg');

    $curl = new Curl();
    echo $curl->Get($urlget, true, "token=12345");
    echo $curl->GetArray($url, $data, true);
    echo $curl->Post($url, $data, $files, true);
    echo $curl->PostJson($url, $data, true);
?>

Php文件:api.php

<?php
    /*
    $Cookie = session_get_cookie_params();
    print_r($Cookie);
    */
    session_set_cookie_params(9000, '/', 'hostname.x', isset($_SERVER["HTTPS"]), true);
    session_start();

    $_SESSION['cnt']++;
    echo "Session count: " . $_SESSION['cnt']. "\r\n";
    echo $json = file_get_contents('php://input');
    $arr = json_decode($json, true);
    echo "<pre>";
    if(!empty($json)){ print_r($arr); }
    if(!empty($_GET)){ print_r($_GET); }
    if(!empty($_POST)){ print_r($_POST); }
    if(!empty($_FILES)){ print_r($_FILES); }
    // request headers
    print_r(getallheaders());
    print_r(apache_response_headers());
    // Fetch a list of headers to be sent.
    // print_r(headers_list());
?>

首先让我们了解curl、libcurl和PHP/ curl的概念。

curl: A command line tool for getting or sending files using URL syntax. libcurl: a library created by Daniel Stenberg, that allows you to connect and communicate to many different types of servers with many different types of protocols. libcurl currently supports the http, https, ftp, gopher, telnet, dict, file, and ldap protocols. libcurl also supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading (this can also be done with PHP's ftp extension), HTTP form based upload, proxies, cookies, and user+password authentication. PHP/cURL: The module for PHP that makes it possible for PHP programs to use libcurl.

如何使用:

step1:使用curl_init()初始化一个curl会话。

step2:设置CURLOPT_URL的选项。这个值就是我们将请求发送到的URL。使用参数“q=”附加搜索词“curl”。设置选项CURLOPT_RETURNTRANSFER, true将告诉curl返回字符串而不是打印出来。设置CURLOPT_HEADER的选项,false将告诉curl忽略返回值中的报头。

step3:使用curl_exec()执行curl会话。

关闭我们创建的curl会话。

step5:输出返回字符串。

制作演示:

您需要创建两个PHP文件,并将它们放入web服务器可以从中提供PHP文件的文件夹中。在我的例子中,为了简单起见,我将它们放在/var/www/中。

1. Helloservice.php和2。demo.php

Helloservice.php非常简单,本质上只是回显它得到的任何数据:

<?php
  // Here is the data we will be sending to the service
  $some_data = array(
    'message' => 'Hello World', 
    'name' => 'Anand'
  );  

  $curl = curl_init();
  // You can also set the URL you want to communicate with by doing this:
  // $curl = curl_init('http://localhost/echoservice');

  // We POST the data
  curl_setopt($curl, CURLOPT_POST, 1);
  // Set the url path we want to call
  curl_setopt($curl, CURLOPT_URL, 'http://localhost/demo.php');  
  // Make it so the data coming back is put into a string
  curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
  // Insert the data
  curl_setopt($curl, CURLOPT_POSTFIELDS, $some_data);

  // You can also bunch the above commands into an array if you choose using: curl_setopt_array

  // Send the request
  $result = curl_exec($curl);

  // Get some cURL session information back
  $info = curl_getinfo($curl);  
  echo 'content type: ' . $info['content_type'] . '<br />';
  echo 'http code: ' . $info['http_code'] . '<br />';

  // Free up the resources $curl is using
  curl_close($curl);

  echo $result;
?>

2.demo.php页面,你可以看到结果:

<?php 
   print_r($_POST);
   //content type: text/html; charset=UTF-8
   //http code: 200
   //Array ( [message] => Hello World [name] => Anand )
?>

cURL

cURL是一种从代码中命中URL以从中获得HTML响应的方法。 它用于PHP语言的命令行cURL。 cURL是一个允许您在PHP中发出HTTP请求的库。

PHP支持libcurl,这是Daniel Stenberg创建的库,它允许您使用许多不同类型的协议连接和通信到许多不同类型的服务器。Libcurl目前支持http、https、ftp、gopher、telnet、dict、file和ldap协议。libcurl还支持HTTPS证书、HTTP POST、HTTP PUT、FTP上传(这也可以用PHP的FTP扩展完成)、基于HTTP表单的上传、代理、cookie和用户+密码身份验证。

在编译了支持cURL的PHP之后,就可以开始使用cURL函数了。cURL函数背后的基本思想是使用curl_init()初始化一个cURL会话,然后可以通过curl_setopt()设置传输的所有选项,然后可以使用curl_exec()执行会话,然后使用curl_close()结束会话。

示例代码

// error reporting
error_reporting(E_ALL);
ini_set("display_errors", 1);

//setting url
$url = 'http://example.com/api';

//data
$data = array("message" => "Hello World!!!");

try {
    $ch = curl_init($url);
    $data_string = json_encode($data);

    if (FALSE === $ch)
        throw new Exception('failed to initialize');

        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, false);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array( 'Content-Type: application/json', 'Content-Length: ' . strlen($data_string)));
        curl_setopt($ch, CURLOPT_TIMEOUT, 5);
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);

        $output = curl_exec($ch);

    if (FALSE === $output)
        throw new Exception(curl_error($ch), curl_errno($ch));

    // ...process $output now
} catch(Exception $e) {

    trigger_error(sprintf(
        'Curl failed with error #%d: %s',
        $e->getCode(), $e->getMessage()),
        E_USER_ERROR);
}

如需更多信息,请查看-

旋度 旋度函数

cURL是一个允许您在PHP中发出HTTP请求的库。您需要了解的关于它(以及大多数其他扩展)的一切都可以在PHP手册中找到。

为了使用PHP的cURL函数 您需要安装»libcurl 包中。PHP要求您使用 Libcurl 7.0.2 beta或更高版本。在PHP中 4.2.3,您需要libcurl版本7.9.0或更高。从PHP 4.3.0开始,您将需要一个libcurl版本 7.9.8或更高。PHP 5.0.0需要libcurl 7.10.5或更高版本。

您也可以在没有cURL的情况下进行HTTP请求,尽管它需要在php.ini文件中启用allow_url_fopen。

// Make a HTTP GET request and print it (requires allow_url_fopen to be enabled)
print file_get_contents('http://www.example.com/');

cURL是一种从代码中命中URL以获得html响应的方法。cURL的意思是客户端URL,它允许你与其他URL连接,并在你的代码中使用它们的响应。