libnbd-ocaml(3)                     LIBNBD                     libnbd-ocaml(3)


NAME
       libnbd-ocaml - how to use libnbd from OCaml

SYNOPSIS
        let nbd = NBD.create () in
        NBD.connect_uri nbd "nbd://localhost";
        let size = NBD.get_size nbd in
        printf "%Ld\n" size;
        NBD.close ()

       Alternate syntax which ensures that close is called even if an
       exception is thrown:

        let size =
          NBD.with_handle (
            fun nbd ->
              NBD.connect_uri nbd "nbd://localhost";
              NBD.get_size nbd
          ) in
        printf "%Ld\n" size

       To compile:

        ocamlopt -I +nbd mlnbd.cmxa prog.ml -o prog

       or using findlib:

        ocamlfind opt -package nbd -linkpkg prog.ml -o prog

DESCRIPTION
       This manual page documents how to use libnbd to access Network Block
       Device (NBD) servers from the OCaml programming language.

       The OCaml bindings work very similarly to the C bindings so you should
       start by reading libnbd(3).

       For OCaml API documentation see NBD(3).

HANDLES
       Create a libnbd handle of type "NBD.t" by calling "NBD.create ()".

       You can either close the handle explicitly by calling "NBD.close" or it
       will be closed automatically when it is garbage collected.  If you call
       any other method on a handle which you have explicitly closed then the
       API will throw an "NBD.Closed" exception.

       "NBD.with_handle" can be used to make sure the handle is closed in a
       timely manner.  See the example in the "SYNOPSIS" above.

ERRORS
       Libnbd errors are turned automatically into exceptions of type:

        NBD.Error (str, Unix.error option)

       The first exception parameter is a string which is the printable error
       message.  The second is the OCaml "Unix.error" code, if available (see
       nbd_get_errno(3)).

   Callbacks with "int ref" error parameter
       Some callbacks take an error parameter of type "int ref", corresponding
       to the "int *error" passed to those callbacks in C.  See also:
       "Callbacks with "int *error" parameter" in libnbd(3)

       If an error occurs during the callback you can update the "int" in the
       reference, setting it to a C-compatible errno.  To convert an OCaml
       "Unix.error" into a C-compatible errno call "NBD.errno_of_unix_error".

EXAMPLES
       This directory contains examples written in OCaml:

       https://gitlab.com/nbdkit/libnbd/tree/master/ocaml/examples

SEE ALSO
       libnbd(3), NBD(3).

AUTHORS
       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-1.20.0                     2024-05-31                   libnbd-ocaml(3)