How to find out the real path of an file in Sharepoint?

Question

I am currently trying to write an application using C# that accesses a file stored on a SharePoint server programatically using the REST API. For that purpose, I want to check out a file. The file exists at this path:

http://myserver.mydomain.com/sites/MyCompany/012_MyDepartment/Shared%20Documents/rm/MyToolConfig/config.xml

When I paste this line in my browser, I see the file.

Next thing I do is to use REST like this:

http://myserver.mydomain.com/_api/web/GetFileByServerRelativeUrl('/sites/MyCompany/012_MyDepartment/Shared%20Documents/rm/MyToolConfig/config.xml')/CheckOut()

According to the REST-documentation, this should work. However, when I paste this path to my browser, I get the following error:

<m:error xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
<m:code>-2146232832, Microsoft.SharePoint.SPException</m:code>
<m:message xml:lang="en-US">
The file /sites/MyCompany/012_MyDepartment/Shared%20Documents/rm/MyToolConfig/config.xml does not exist.
</m:message>
</m:error>

So the question is: is it possible that the server maps the physical path of the file internally to another location? How can I figure out what the correct path is that needs to be passed to the function "GetFileByServerRelativeUrl"?

Please note that I do not administrate that SharePoint server, I only have to use it as a "black box" to store and get files from.

EDIT: Here is some sample code I currently use:

const string serverName = @"http://myserver.mydomain.com/sites/MyCompany/_api/web/GetFileByServerRelativeUrl('/sites/MyCompany/012_MyDepartment/Shared%20Documents/rm/MyToolConfig/config.xml')/CheckOut()";            
HttpWebRequest req = WebRequest.Create(serverName) as HttpWebRequest;
req.Method = "POST";
req.Credentials = CredentialCache.DefaultCredentials; 
req.Headers.Add("X-RequestDigest", GetFormDigest());
req.ContentLength = 0;
HttpWebResponse myWebResponse = (HttpWebResponse)req.GetResponse();

Answer 1

You should do it like this:

http://myserver.mydomain.com/sites/MyCompany/_api/web/GetFileByServerRelativeUrl('/sites/MyCompany/012_MyDepartment/Shared%20Documents/rm/MyToolConfig/config.xml')/CheckOut()

And Request should be POST.

Hopefully this helps.