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