How to display binary data from curl in php

问题

I'm writing simple php proxy and I have trouble displaying png file, the output is

and it should be:

The images are opened in Notepad++. My php curl code look like this:

$ua = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_USERAGENT, $ua);
curl_setopt($ch, CURLOPT_HEADER_OUT, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
$content = curl_exec($ch);
$info = curl_getinfo($ch);
header('Content-Type:' . $info['content_type']);
echo $content

I try with and without CURLOPT_BINARYTRANSFER the output is the same and the image is not displaying. How can I display the image?

EDIT: when I'm saving the data to the file and redirect using Location header the image is displayed correctly:

$file = fopen('proxy_tmp~', 'w');
fwrite($file, $content);
fclose($file);
header('Location: ' . DIR . 'proxy_tmp~');

EDIT 2: I had gzip compression, bu when I disabled it I have the same issue, when I open both files in Notepad++ one is DOS/Windows ANSI (original) and the other is DOS/Windows UTF-8 (the file opened by a script). When I open a file in Notepad and change encoding to ANSI and save the file, everything is ok.

EDIT 3: I think I did the same thing on GNU/Linux but without CURLOPT_BINARYTRANSFER option and it's working fine, here is my project https://github.com/jcubic/yapp. I've also test it on Windows 10 with Wamp and also work fine.

回答1:

Here is how to send the file directly back to the user for download (uses your $content var):

$file_array = explode("\n\r", $content, 2);
$header_array = explode("\n", $file_array[0]);
foreach($header_array as $header_value) {
$header_pieces = explode(':', $header_value);
  if(count($header_pieces) == 2) {
    $headers[$header_pieces[0]] = trim($header_pieces[1]);
  }
}
header('Content-type: ' . $headers['Content-Type']);
header('Content-Disposition: ' . $headers['Content-Disposition']);
echo substr($file_array[1], 1);

There is a full example here:

http://ryansechrest.com/2012/07/send-and-receive-binary-files-using-php-and-curl/

回答2:

Which php version are you using? Are you above PHP version 5.1.3? Then the CURLOPT_BINARYTRANSFER will have no effect.

Source: http://php.net/manual/en/function.curl-setopt.php

Looking at the file, you should add the following header to you're page:

header('Content-Type: image/png');

回答3:

I have used following with basic header authentication.. used postman to get auth key

// key : > converted to basic auth

// Content type
header('Content-Type: image/jpeg');

$url = 'http://com.com.com/api/images/products/264/7971';
$headers = array(
    'Content-Type: image/png',
    'Authorization: Basic @#$%@#$%@#$%@#$%@#$%@#$%' );

$ch = curl_init();
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
//curl_setopt($ch, CURLOPT_USERPWD, "$login:$password");
$file = curl_exec($ch);
curl_close($ch);  
//echo($result);

// create image from output of the screen
$img = @imagecreatefromstring($file);

if ($img === false) {
    echo $file;
    exit;
}

$width = imagesx($img);
$height = imagesy($img);

$newWidth = 300;

$ratio = $newWidth / $width;
$newHeight = $ratio * $height;


$resized = @imagecreatetruecolor($newWidth, $newHeight);

if ($resized === false) {
    echo $file;
    exit;
}

$quality = 90;

if (@imagecopyresampled($resized, $img, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height)) {
    @imagejpeg($resized, NULL, $quality);
} else {
    echo $file;
}

回答4:

Use $content_arr = explode("\r\n\r\n",$content,2); to divide the content into headers and body, set the image/png header and then do echo trim($content_arr[1]); to get rid of spaces or blank lines that prevent the browser from being able to read the image.

回答5:

In my case adding Content-Length header fixed problems with binary files proxy.

来源：https://stackoverflow.com/questions/17520987/how-to-display-binary-data-from-curl-in-php

标签

php

image

curl

binary-data