Curl upload file PHP

There are "@" issue on multipart POST requests.

Solution for PHP 5.5 or later:
- Enable CURLOPT_SAFE_UPLOAD.
- Use CURLFile instead of "@".

Solution for PHP 5.4 or earlier:
- Build up multipart content body by youself.
- Change "Content-Type" header by yourself.

The following snippet will help you :D

<?php
/**
* For safe multipart POST request for PHP5.3 ~ PHP 5.4.
*
* @param resource $ch cURL resource
* @param array $assoc "name => value"
* @param array $files "name => path"
* @return bool
*/function curl_custom_postfields($ch, array $assoc = array(), array $files = array()) {
   
    // invalid characters for "name" and "filename"
    static $disallow = array("\0", "\"", "\r", "\n");
   
    // build normal parameters
    foreach ($assoc as $k => $v) {
        $k = str_replace($disallow, "_", $k);
        $body[] = implode("\r\n", array(
            "Content-Disposition: form-data; name=\"{$k}\"",
            "",
            filter_var($v),
        ));
    }
   
    // build file parameters
    foreach ($files as $k => $v) {
        switch (true) {
            case false === $v = realpath(filter_var($v)):
            case !is_file($v):
            case !is_readable($v):
                continue; // or return false, throw new InvalidArgumentException
        }
        $data = file_get_contents($v);
        $v = call_user_func("end", explode(DIRECTORY_SEPARATOR, $v));
        $k = str_replace($disallow, "_", $k);
        $v = str_replace($disallow, "_", $v);
        $body[] = implode("\r\n", array(
            "Content-Disposition: form-data; name=\"{$k}\"; filename=\"{$v}\"",
            "Content-Type: application/octet-stream",
            "",
            $data,
        ));
    }
   
    // generate safe boundary
    do {
        $boundary = "---------------------" . md5(mt_rand() . microtime());
    } while (preg_grep("/{$boundary}/", $body));
   
    // add boundary for each parameters
    array_walk($body, function (&$part) use ($boundary) {
        $part = "--{$boundary}\r\n{$part}";
    });
   
    // add final boundary
    $body[] = "--{$boundary}--";
    $body[] = "";
   
    // set options
    return @curl_setopt_array($ch, array(
        CURLOPT_POST       => true,
        CURLOPT_POSTFIELDS => implode("\r\n", $body),
        CURLOPT_HTTPHEADER => array(
            "Expect: 100-continue",
            "Content-Type: multipart/form-data; boundary={$boundary}", // change Content-Type
        ),
    ));
}
?>