nbd_get_uri(3)                      LIBNBD                      nbd_get_uri(3)


NAME
       nbd_get_uri - construct an NBD URI for a connection

SYNOPSIS
        #include <libnbd.h>

        char * nbd_get_uri (
                 struct nbd_handle *h
               );

DESCRIPTION
       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.

       nbdinfo(1) --uri option is a way to access this API from shell scripts.

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

ERRORS
       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
       nbd_get_uri can be called when the handle is in the following states:

        <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
        | Handle created, before connecting   | <?> error                |
        | Connecting                          | <?> allowed              |
        | Connecting & handshaking (opt_mode) | <?> allowed              |
        | Connected to the server             | <?> allowed              |
        | Connection shut down                | <?> allowed              |
        | Handle dead                         | <?> allowed              |
        <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>

VERSION
       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:

        #define LIBNBD_HAVE_NBD_GET_URI 1

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_is_uri(3),
       nbd_supports_uri(3), libnbd(3), nbdinfo(1).

AUTHORS
       Eric Blake

       Richard W.M. Jones

COPYRIGHT
       Copyright Red Hat

LICENSE
       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

libnbd-1.24.3                     2026-07-16                    nbd_get_uri(3)