Posting raw image data as multipart/form-data in curl

Question

I am trying to post an image with cURL in PHP using multipart/form-data header since API that I am sending to is expecting image to be sent as multi-part form.

I don't have problems talking to the API with other requests; only posting an image is an issue.

I am using this form on client side:

<form action="http://myServerURL" method="POST" enctype="multipart/form-data">     <input type="file" name="file" />     <input type="Submit"> </form> 

and this is the server I am posting to (here I am trying to post this data forward to an API):

$ch = curl_init($url); curl_setopt ($ch, CURLOPT_POST, 1); curl_setopt ($ch, CURLOPT_POSTFIELDS, $imgRawData); // <-- raw data here hm? curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1); curl_setopt ($ch, CURLOPT_COOKIEFILE, $cookieJar); curl_setopt( $ch, CURLOPT_HEADER, 1); curl_setopt($ch, CURLINFO_HEADER_OUT, 1); <-- using this as I wanted to check if HTTPHEADER is set curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: multipart/form-data')); <-- setting content-type header? curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1);  // i get response from the server $response = curl_exec( $ch );  // with this I can check what kind of content type the last request had? $requestContentType = curl_getinfo($ch,CURLINFO_CONTENT_TYPE); echo "<br>request Content Type was:".$requestContentType."<br>";      curl_close($ch);  echo "<br><b>SERVER POST IMAGE RESPONSE:</b><br>"; echo $response; 

With the code below I am able to see my request headers:

curl_setopt($ch, CURLOPT_HEADER, 1); curl_setopt($ch, CURLINFO_HEADER_OUT, true);  var_dump(curl_getinfo($ch)); 

The content-type in request-headers is shown correctly now. But it seems the image is not send correctly as API would expect. Unfortunately I don't have access to the API...

Any help appreciated, thank you

Answer 1

As of PHP 5.6 @$filePath will not work in CURLOPT_POSTFIELDS without CURLOPT_SAFE_UPLOAD being set and it is completely removed in PHP 7. You will need to use a CurlFile object, RFC here.

$fields = [     'name' => new \CurlFile($filePath, 'image/png', 'filename.png') ]; curl_setopt($resource, CURLOPT_POSTFIELDS, $fields); 

Answer 2

In case anyone had the same problem: check this as @PravinS suggested. I used the exact same code as shown there and it worked for me perfectly.

This is the relevant part of the server code that helped:

if (isset($_POST['btnUpload'])) { $url = "URL_PATH of upload.php"; // e.g. http://localhost/myuploader/upload.php // request URL $filename = $_FILES['file']['name']; $filedata = $_FILES['file']['tmp_name']; $filesize = $_FILES['file']['size']; if ($filedata != '') {     $headers = array("Content-Type:multipart/form-data"); // cURL headers for file uploading     $postfields = array("filedata" => "@$filedata", "filename" => $filename);     $ch = curl_init();     $options = array(         CURLOPT_URL => $url,         CURLOPT_HEADER => true,         CURLOPT_POST => 1,         CURLOPT_HTTPHEADER => $headers,         CURLOPT_POSTFIELDS => $postfields,         CURLOPT_INFILESIZE => $filesize,         CURLOPT_RETURNTRANSFER => true     ); // cURL options     curl_setopt_array($ch, $options);     curl_exec($ch);     if(!curl_errno($ch))     {         $info = curl_getinfo($ch);         if ($info['http_code'] == 200)             $errmsg = "File uploaded successfully";     }     else     {         $errmsg = curl_error($ch);     }     curl_close($ch); } else {     $errmsg = "Please select the file"; } } 

html form should look something like:

<form action="uploadpost.php" method="post" name="frmUpload" enctype="multipart/form-data"> <tr>   <td>Upload</td>   <td align="center">:</td>   <td><input name="file" type="file" id="file"/></td> </tr> <tr>   <td>&nbsp;</td>   <td align="center">&nbsp;</td>   <td><input name="btnUpload" type="submit" value="Upload" /></td> </tr>