Simulating a form uploading a file to a server

I have an HTML form like:

<form method="post" enctype="multipart/form-data">
<input type="file" name="file_name">
<input type=submit>
</form>

Code (markup):

I want to simulate a user submitting the form and I think the curl library is probably the way to do it. So I wrote this function:

function upload_file($path_to_file)
{
    $url = 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['SCRIPT_NAME'];
    $postData = array();
    $postData['file_name'] = $path_to_file;
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url );
    curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
    curl_setopt($ch, CURLOPT_POST, 1 );
    curl_setopt($ch, CURLOPT_POSTFIELDS, $postData );
    $response = curl_exec( $ch );
}

Code (markup):

If I send this to phpinfo(), I see the normal $_POST array but no $_FILE array. If I actually submit the form without curl, I see the $_FILE array as expected.

After reading the curl man pages, I tested on the command line:

me@mybox:~$ curl -F filename=/home/me/myimg.gif http://127.0.0.1/pi.php
_REQUEST["filename"] = /home/me/myimg.gif
_POST["filename"] = /home/me/myimg.gif

Code (markup):

Still no $_FILE array. Second test (man page says prefacing with @ will force the encoding to be multipart):

me@mybox:~$ curl -F filename=@/home/me/myimg.gif http://127.0.0.1/pi.php
curl: (26) failed creating formpost data

Code (markup):

I'm wondering if anybody out there has ever successfully simulated submitting a form via curl to upload a file?

TIA

 

_FILES is a superglobal that's only populated when a file is uploaded, curl doesn't have the ability to simulate that I don't think.

 

curl more or less emulates a browser call and the only difference the server sees is the user-agent. Because I have been beating my head against the wall all day with this, I didn't notice that I had allowed a typo in the file name. Once I fixed that, I was able to make the call from the command line successfully so I went back to my original problem. (A curl error #26 will only occur if the file is unable to be read or non-existent.)

My original problem is this: I've got a form from which I can upload an image. On a change to the input value (<input type=file>, I want to do an AJAX call so I can populate the form with a preview of the image. If I pass the path/to/file value that is populated in the form to my php script and do a curl call with that pure ($postData['file_name'] = "$img") value, it doesn't create the _FILE structure but the _POST is populated. If I call it as $postData['file_name'] = "@$img", I get an error #26 (the file is nonexistent which is logical because it exists only on the local machine, not the server)

I think it has to be a matter of 2 separate forms and I should probably refer this question to some AJAX gurus for a possible solution.

I've learned a couple of things as I've gotten older. First, if I had realized I was gonna live so long, I'd have started saving for retirement a lot sooner. Second, I shouldn't have ignored Javascript for as long as I have. Doh!