PHP's fopen() can't get url, but curl can - php

Question

A while back, I wrote a little utility function that takes inPath and outPath, opens both and copies from one to the other using fread() and fwrite(). allow_url_fopen is enabled.
Well, I've got a url that I'm trying to get the contents of, and fopen() doesn't get any data, but if I use curl to do the same, it works.
The url in question is: http://www.deltagroup.com/Feeds/images.php?lid=116582497&id=1
fopen version:
$in = #fopen( $inPath, "rb" );
$out = #fopen( $outPath, "wb" );
if( !$in || !$out )
{
echo 0;
}
while( $chunk = fread( $in, 8192 ) )
{
fwrite( $out, $chunk, 8192 );
}
fclose( $in );
fclose( $out );
if( file_exists($outPath) )
{
echo 1;
}
else
{
echo 0;
}
curl version:
$opt = "curl -o " . $outPath . " " . $inPath;
$res = `$opt`;
if( file_exists($outPath) )
{
echo 1;
}
else
{
echo 0;
}
Any idea why this would happen?

Answer 1

Even using php's curl, I was unable to download the file- until I added a curlopt_useragent string. Nothing in the response indicated that it was required (no errors, nothing other than an HTTP 200).
Final code:
$out = #fopen( $outPath, "wb" );
if( !$out )
{
echo 0;
}
$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL, $inPath );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt( $ch, CURLOPT_FILE, $out );
curl_setopt( $ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 6.1; en; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13');
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, 15 );
curl_setopt( $ch, CURLOPT_TIMEOUT, 18000 );
$data = curl_exec( $ch );
curl_close( $ch );
fclose( $out );
if( file_exists($outPath) )
{
echo 1;
}
else
{
echo 0;
}