nbd_get_uri - Man Page

construct an NBD URI for a connection


 #include <libnbd.h>

 char * nbd_get_uri (
          struct nbd_handle *h


This makes a best effort attempt to construct an NBD URI which could be used to connect back to the same server (using nbd_connect_uri(3)).

In some cases there is not enough information in the handle to successfully create a URI (eg. if you connected with nbd_connect_socket(3)).  In such cases the call returns NULL and further diagnostic information is available via nbd_get_errno(3) and nbd_get_error(3) as usual.

Even if a URI is returned it is not guaranteed to work, and it may not be optimal.

Return Value

This call returns a string.  The caller must free the returned string to avoid a memory leak.


On error NULL is returned.

Refer to "ERROR HANDLING" in libnbd(3) for how to get further details of the error.

The following parameters must not be NULL: h. For more information see "Non-NULL parameters" in libnbd(3).

Handle State

The handle must be connecting, or negotiating, or connected with the server, or shut down, or dead, otherwise this call will return an error.


This function first appeared in libnbd 1.8.

If you need to test if this function is available at compile time check if the following macro is defined:


See Also

nbd_aio_connect_uri(3), nbd_connect_socket(3), nbd_connect_uri(3), nbd_create(3), nbd_get_errno(3), nbd_get_error(3), nbd_supports_uri(3), libnbd(3).


Eric Blake

Richard W.M. Jones


This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Referenced By

libnbd(3), libnbd-release-notes-1.10(1), libnbd-release-notes-1.8(1), NBD(3), nbd_connect_uri(3), nbd_supports_uri(3).

2023-09-08 libnbd-1.17.5