便利なやつをみつけたのでメモ。

function curl_file_get_contents($url)
{
   $curl = curl_init();
    $userAgent = 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.1.4322)';
 
    curl_setopt($curl,CURLOPT_URL,$url); //The URL to fetch. This can also be set when initializing a session with curl_init().
    curl_setopt($curl,CURLOPT_RETURNTRANSFER,TRUE); //TRUE to return the transfer as a string of the return value of curl_exec() instead of outputting it out directly.
    curl_setopt($curl,CURLOPT_CONNECTTIMEOUT,5); //The number of seconds to wait while trying to connect.	
 
    curl_setopt($curl, CURLOPT_USERAGENT, $userAgent); //The contents of the "User-Agent: " header to be used in a HTTP request.
    curl_setopt($curl, CURLOPT_FAILONERROR, TRUE); //To fail silently if the HTTP code returned is greater than or equal to 400.
    curl_setopt($curl, CURLOPT_FOLLOWLOCATION, TRUE); //To follow any "Location: " header that the server sends as part of the HTTP header.
    curl_setopt($curl, CURLOPT_AUTOREFERER, TRUE); //To automatically set the Referer: field in requests where it follows a Location: redirect.
    curl_setopt($curl, CURLOPT_TIMEOUT, 10); //The maximum number of seconds to allow cURL functions to execute.	
 
    $contents = curl_exec($curl);
    curl_close($curl);
    return $contents;
}

file_get_contentsよりもcurlのほうが倍以上パフォーマンス優れてるし、これは便利。