[SalesForce] URL_NOT_RESET error REST API

You're very close - the tricky bit is that the Chatter REST API is expecting a multipart form. Also, it wants the message segments as its own array. After some poking around it looks like the easiest way to handle it is by wrangling the post data together.

I'm using this doc as a base: http://www.salesforce.com/us/developer/docs/chatterapi/Content/intro_input.htm

And here is my script, note that I pasted the url manually (which you should not):

    <?php
    $url = "https://na15.salesforce.com/services/data/v29.0/chatter/feeds/record/500i0000004AcIq/feed-items";
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");

    $fileName = basename($file);

    $headers = array();
    $headers[] = "Authorization: OAuth {token}";
    $headers[] = 'Content-Type: multipart/form-data; boundary=F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI';

    $segments = array();
    $segments['type'] = 'Text';
    $segments['text'] = 'User uploaded attachment';

    $message = array();
    $message[] = $segments;

    $dataArray = array(
        'body' => array(
            'messageSegments' => $message
        ),
        'attachment' => array(
            'attachmentType' => 'NewFile',
            'title' => 'Test File'
        )
    );

    $data = $data.json_encode($dataArray);
    $file = realpath('phoenix-logo.png');


    $post_text = '--F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI
Content-Disposition: form-data; name="json"
Content-Type: application/json; charset=UTF-8

{ "body":
   {
      "messageSegments" : [
      {
         "type" : "Text", 
         "text" : "Here is another file for review."
      }, {
         "type" : "Hashtag", 
         "tag" : "important"
      }, {
         "type" : "Text", 
         "text" : "Again, please review this as soon as possible."
      }
      ]
   }, 
   "attachment": 
   {
      "attachmentType" : "NewFile",
      "description": "Phoenix Logo",
      "title" : "Logo.png"
   }
}

--F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI
Content-Disposition: form-data; name="feedItemFileUpload"; filename="logo.png"
Content-Type: image/png

'.file_get_contents($file).'

--F9jBDELnfBLAVmLNbnLIYibT5Icp0h3VJ7mkI--';

    curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_VERBOSE, 1);
    curl_setopt($curl, CURLOPT_POSTFIELDS, $post_text);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLINFO_HEADER_OUT, true);

    $response_json = curl_exec($curl);

    print $response_json;
    ?>

For others having the same issue you could be missing the security token:

For access via the API or client app, if the Multi-Factor Authentication on API Logins permission is set on the user profile, users enter a TOTP verification code generated by an authenticator app. If the permission isn’t set, users must add their security token to the end of their password to log in. A security token is a generated key from Salesforce. For example, if a user’s password is mypassword and the security token is XXXXXXXXXX, the user enters mypasswordXXXXXXXXXX to log in. Some client apps have a separate field for the security token.

Users can get their security token by changing their password or resetting their security token via the Salesforce user interface. When a user changes a password or resets a security token, Salesforce sends a new security token to the email address on the user’s Salesforce record. The security token is valid until the user resets the security token, changes a password, or has a password reset.

Reference: https://developer.salesforce.com/docs/atlas.en-us.api.meta/api/sforce_api_concepts_security.htm