如何在PHP 8.2中从CURL响应获取Location URL

我在PHP 8.2中使用CURL发送POST请求时，收到了301重定向响应，需要提取响应头里Location对应的URL。我的请求代码如下：

$arrPostFields = [
    'data_one' => $this->getDataOne,
    'data_two' => $this->getDataTwo
];

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $this->apiUrl);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $arrPostFields);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);

$response = curl_exec($ch);

得到的响应内容：

HTTP/1.1 301 Moved Permanently
Date: Tue, 02 May 2023 11:16:23 GMT
Transfer-Encoding: chunked
Connection: keep-alive
Location: https://example.com/?url=aHffR0cgrHM6Ly9lY29tbWVyY2UudGJpYmFuay5yby9Mb2FuT3JpZ2luYXRpb25fQjJDUHJveHkvZWM/c2Vzc2lvbklkPTkyMTdiZTJkLTdjMjgtNDY1Yy1hMWYzLTNmNGNlNmJlZTMzZSZjdWx0dXJlPXJvLVJP&link2payid=f880864b-2cd5-4b95-bd53-ea65b0b46063
Server: Microsoft-IIS/10.0
X-Powered-By: ASP.NET

方案一：使用CURL内置方法（推荐） #

直接通过CURL内置函数获取重定向URL，无需手动解析响应头。只需在CURL选项中添加CURLOPT_FOLLOWLOCATION设为false，再用curl_getinfo()提取：

$arrPostFields = [
    'data_one' => $this->getDataOne,
    'data_two' => $this->getDataTwo
];

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $this->apiUrl);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $arrPostFields);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
// 禁止自动跟随重定向，保留301响应
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);

$response = curl_exec($ch);
// 直接获取Location头部的URL
$locationUrl = curl_getinfo($ch, CURLINFO_REDIRECT_URL);

这种方法更可靠，避免了手动解析字符串可能出现的格式问题。

方案二：手动解析响应头字符串 #

如果无法修改CURL配置，可以拆分响应内容，手动提取Location字段：

// $response为curl_exec返回的完整响应内容
$headerLines = preg_split("/\r\n|\n|\r/", $response);
$locationUrl = '';

foreach ($headerLines as $line) {
    if (str_contains($line, 'Location:')) {
        // 拆分后去除前后多余空格
        $locationUrl = trim(explode('Location:', $line)[1]);
        break; // 找到后直接退出循环，提升效率
    }
}

通过正则拆分响应的每一行，定位到Location:所在行后拆分出URL，并用trim()去除可能存在的前后空格。

内容的提问来源于stack exchange，提问作者calin24