How to solve the problem of curl returning false in php? (example explanation)

This article introduces the solutions to the problems I encountered when using curl. Hope it helps everyone.

First let’s look at an encapsulated curl function

function request_post($url = '', $param = '') {
    if (empty($url) || empty($param)) {
        return false;
    }
    $postUrl = $url;
    $curlPost = $param;
    $curl = curl_init();//初始化curl
    curl_setopt($curl, CURLOPT_URL,$postUrl);//抓取指定网页
    curl_setopt($curl, CURLOPT_HEADER, 0);//设置header
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);//要求结果为字符串且输出到屏幕上
    curl_setopt($curl, CURLOPT_POST, 1);//post提交方式
    curl_setopt($curl, CURLOPT_POSTFIELDS, $curlPost);//提交的参数
    $data = curl_exec($curl);//运行curl
    curl_close($curl);
    
    return $data;
}

When called, the return result is bool(false)
We are in the curl_exec function The error obtained earlier through curl_error($curl) is also string(0) "" empty string.

Finally I found that the interface address of the API I called was ssl protocol, and then just add the following two

curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);

Ifcurl If the requested address contains spaces, false will also be returned. Pay special attention to this.

I have also encountered one before that returns falseprintcurl_error( $curl)What I get is the following error

string(39) "Problem (2) in the Chunked-Encoded data" bool(false)

The solution to this error is to set the HTTP protocol version used by curl, which is to add the following sentence

//CURL_HTTP_VERSION_1_0 (强制使用 HTTP/1.0)
//CURL_HTTP_VERSION_1_1 (强制使用 HTTP/1.1)。
curl_setopt($curlp, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);

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