php - use curl to pass file from one server to another -

i have web server receives posted data form, 1 part of can attached image. want use curl send information along second server. works fine requests not include image, when image included in original post get:

curl error 26: failed creating formpost data 

i know indicates curl unable find file, having trouble determining why not. here code

if ($_post) {   $postdata = array();       //copy in post fields posted here       foreach ($_post $key => $value) {     $postdata[$key] = $value;     }   //copy in files have been included   foreach ($_files $key => $value) {     if ($value["tmp_name"]) { //if null, no file uploaded                     $fn = "existing_image.jpg";//(use existing debugging                                  //in reality, use tmp image)                  $postdata[$key] = "@" . realpath($fn) . ";type=" . $value["type"];        $testmsg .= "added file $key value of '" . $postdata[$key] .           "'(" . file_exists($fn) . ")\n";     }   }    $testmsg .= "postdata:\n" . print_r($postdata, true);    $options[curlopt_post] = true;           $options[curlopt_postfields] = $postdata;   } 

and here output:

added file photo value of '@/var/www/wordpress/somedirectory/php/existing_image.jpg;type=image/jpeg'(1) postdata: array (     [key1] => 4     [key2] => blah blah text     [key3] => etc     [keyimage] => @/var/www/wordpress/somedirectory/php/existing_image.jpg;type=image/jpeg ) 

the file indeed exists - why curl giving me error? appreciate can give...

edit: not have same problem when servers 1 , 2 same server (i.e. when set web page on second server receives posted data , executes same curl code send info along itself). means something, evidently overlooking something...

i'm not sure perhaps php or curl version doesn't support setting content type way. try remove type= part code , let curl decide content type:

$postdata[$key] = "@" . realpath($fn); 

you try setting curlopt_verbose flag true , see if more descriptive error message.