<?php

function dlfile1($file_url, $save_to)

{

	$in = fopen($file_url, "rb");

	$out = fopen($save_to, "wb");

	while ($chunk = fread($in,8192))

	{

		fwrite($out, $chunk, 8192);

	}

	fclose($in);

	fclose($out);

}

function dlfile_curl($file_url, $save_to)			// 不支持https

{

	$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);

	if(!$file_content)

	{

		echo "download file failed";

		return;

	}

	$downloaded_file = fopen($save_to, 'w');

	fwrite($downloaded_file, $file_content);

	fclose($downloaded_file);

}

function dlfile3($file_url, $save_to)

{

	$content = file_get_contents($file_url);

	file_put_contents($save_to, $content);

}

$url = "https://mp.weixin.qq.com/cgi-bin/showqrcode?ticket=gQFM8TwAAAAAAAAAAS5odHRwOi8vd2VpeGluLnFxLmNvbS9xLzAyM1lwVXBCRWNkQ20xNmV5TDFwMUQAAgSO1QdZAwQAjScA";

//$url = 'http://avatar.csdn.net/9/D/D/1_iefreer.jpg';

dlfile3($url, 'aaa.jpg');