php-curl函数

PHP支持的由Daniel Stenberg创建的libcurl库允许你与各种的服务器使用各种类型的协议进行连接和通讯。

简单说就是使用curl可以实现各种的外部访问请求，今天为什么会想着记录一下curl，是因为遇到了curl外部接口失败的问题。

使用cURL一般有以下几个简单步骤：

1、初始化一个会话
2、设置 cURL 传输选项
3、执行会话
4、关闭会话

下面通过一个简单的例子来说明这4个步骤

这里主要记录一下curl_init和curl_error;

curl_init(): 初始化一个cURL会话。失败时返回false
curl_error(resource $ch）返回一个保护当前会话最近一次错误的字符串

示例：

<?php
// 创建一个新cURL资源
$ch = curl_init();
var_dump($ch);
 
// 设置URL和相应的选项
curl_setopt($ch, CURLOPT_URL, "http://www.baidu.com/");
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
curl_setopt($ch, CURLOPT_HTTPHEADER, []);
curl_setopt($ch, CURLOPT_COOKIE, "cookie");
 
var_dump("ch->>>>>" . var_export($ch, true));
// 抓取URL并把它传递给浏览器
$ret = curl_exec($ch);
 
$errorMsg = curl_error($ch);
var_dump("ret->>>>>" . $ret);
 
// 关闭cURL资源，并且释放系统资源
curl_close($ch);
?>
     
     
}

输出：

resource(4) of type (curl)
string(12) "ch->>>>>NULL"
string(15612) "ret->>>>>HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: no-cache
Connection: keep-alive
Content-Length: 14615
Content-Type: text/html
Date: Sun, 26 Sep 2021 04:01:17 GMT
P3p: CP=" OTI DSP COR IVA OUR IND COM "
P3p: CP=" OTI DSP COR IVA OUR IND COM "
Pragma: no-cache
Server: BWS/1.1
Set-Cookie: BAIDUID=F1CF0784956A2A2854E4135EA0D649FF:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: BIDUPSID=F1CF0784956A2A2854E4135EA0D649FF; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: PSTM=1632628877; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
Set-Cookie: BAIDUID=F1CF0784956A2A280A6821E05BE4A103:FG=1; max-age=31536000; expires=Mon, 26-Sep-22 04:01:17 GMT; domain=.baidu.com; path=/; version=1; comment=bd
Traceid: 163262887703336965229545942739057384109
Vary: Accept-Encoding
X-Frame-Options: sameorigin
X-Ua-Compatible: IE=Edge,chrome=1
 
<!DOCTYPE html><!--STATUS OK-->
<html>
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"
     
     
}