Change name of upload file in cURL?

Question

I want to upload a file using cURL. Since cURL requires full path to the file so here is my code:

curl_setopt($ch, CURLOPT_POSTFIELDS, array("submit" => "submit", "file" => "@path/to/file.ext"));
curl_exec($ch);

However cURL will also post this full path of the file in the request header:

Content-Disposition: form-data; name="file"; filename="/path/to/file.ext"

But I want it to be just

Content-Disposition: form-data; name="file"; filename="file.ext"

So I change the code to

curl_setopt($ch, CURLOPT_POSTFIELDS, array("submit" => "submit", "file" => "@file.ext"));
chdir("path/to"); # change current working directory to where the file is placed
curl_exec($ch);
chdir("path"); # change current working directory back

And then cURL simply throws an error message

couldn't open file "file.ext"

Can anybody tell me how to do it please?

Answer 1

New method (since PHP 5.5) using CURLFile:

$file = new CURLFile('path/to/file.ext');
$file->setPostFilename('file.ext');

use it almost the same:

"file" => $file

Old method:

Instead of

"file" => "@path/to/file.ext"

you can tell cURL to use another filename:

"file" => "@path/to/file.ext; filename=file.ext"

That way it will use path/to/file.ext as file source, but file.ext as filename.

You'll need a very absolute path though, so you're probably missing a leading /: /path/to/file.ext. Since you're using PHP, always do a realpath():

"file" => '@' . realpath($pathToFile) . '; filename=' . basename($pathToFile);

Or something like that.

Answer 2

Please correct me if I'm wrong but cURL upload won't work with relative path. It always need an absolute path, likes

$realpath = realpath($uploadfile);

So if someone wants to hide the location to his file on his webserver when uploading, either move it to a temporary folder or use fsockopen() (see this example in PHP Manual's User Contributed Notes)