PHP下载远程图片的3个方法

1. 使用file_get_contents

function dlfile($file_url, $save_to)
{
    $content = file_get_contents($file_url);
    file_put_contents($save_to, $content);
}

2.使用CURL

function dlfile($file_url, $save_to)
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_POST, 0); 
    curl_setopt($ch,CURLOPT_URL,$file_url); 
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
    $file_content = curl_exec($ch);
    curl_close($ch);
    $downloaded_file = fopen($save_to, 'w');
    fwrite($downloaded_file, $file_content);
    fclose($downloaded_file);
}

3.使用fopen

function dlfile($file_url, $save_to)
{
    $in=    fopen($file_url, "rb"); //rb  read as binary 二进制读取
    $out=   fopen($save_to, "wb");//write as binary 二进制写入 
    while ($chunk = fread($in,8192))
    {
        fwrite($out, $chunk, 8192);
    }
    fclose($in);
    fclose($out);
}