如果圖片存在，從url下載圖片

Question

我有這個網址www.example.com/1.png。我想運行一個循環，像這樣：

for ($i=0; $i<=10; $i++){ 
$url = 'www.example.com/'.$i.'.png'; 
} 

現在我有10倍的網址。可以說10個網址中有7個是圖像，其他3個網站不可用。我想從每個URL下載圖像，如果URL不存在，那麼它不會下載任何東西。

繼承人的同樣的事情，但解釋更basicly我想：

www.example.com/1.png --- url exists, so i download the image and save it in my folder. 
www.example.com/2.png --- url exists, so i download the image and save it in my folder. 
www.example.com/3.png --- url doesnt exist, so i dont download anything 
www.example.com/4.png --- url exists, so i download the image and save it in my folder. 
www.example.com/5.png --- url exists, so i download the image and save it in my folder. 
www.example.com/6.png --- url exists, so i download the image and save it in my folder. 
www.example.com/7.png --- url doesnt exist, so i dont download anything 
www.example.com/8.png --- url exists, so i download the image and save it in my folder. 
www.example.com/9.png --- url exists, so i download the image and save it in my folder. 
www.example.com/10.png --- url doesnt exist, so i dont download anything 

對不起，我的英語不好，有什麼建議，我怎麼能解決這個問題？

Answer 1

您可以檢查標題是否有404錯誤。

$file_headers = @get_headers($url); 
if($file_headers[0] == 'HTTP/1.1 404 Not Found') { 
    //Does not exist 
} 
else 
{ 
    //Exists, so put download code here 
} 

Answer 2

下載與file_get_contents()圖像會產生$http_response_header變量，它包含在HTTP響應頭，你可以檢查。請參閱documentation here