Accessing ROOT Files Remotely via RFIO

Reading and writing ROOT files over the net can be done by creating a TRFIOFile object instead of a TFile object. Since the TRFIOFile class inherits from the TFile class it has exactly the same interface and behaviour. The only difference is that it reads and writes to a remote rfiod daemon.

TRFIOFile URL

rfio:/afs/cern.ch/user/r/rdm/galice.root
rfio:na49db1:/data1/raw.root

The only difference with the well known httpd URL's is that after the protocol specifier (rfio) the files are specified in RFIO format. In the first example given above the file galice.root is a symlink of the type /shift/.../... and this in turn will trigger the RFIO system to open the remote file. The second example is an explicit RFIO remote path name. The expansion of the standard shell characters, like ~, $, .., etc. is handled as expected.

Using the General TFile::Open() Function

         TFile *TFile::Open(const Text_t *name, Option_t *option="",
                       const Text_t *title="",

Depending on the name argument the function returns either a TFile, a TNetFile, a TWebFile or a TRFIOFile object. The arguments of the Open() function are the same as the ones for the TFile constructor.

A Simple Session