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=encoding utf8

=head1 NAME

guestfs-ocaml - How to use libguestfs from OCaml

=head1 SYNOPSIS

Module style:

 let g = Guestfs.create () in
 Guestfs.add_drive_opts g ~format:"raw" ~readonly:true "disk.img";
 Guestfs.launch g;

Object-oriented style:

 let g = new Guestfs.guestfs () in
 g#add_drive_opts ~format:"raw" ~readonly:true "disk.img";
 g#launch ();

 ocamlfind opt prog.ml -package guestfs -linkpkg -o prog
or:
 ocamlopt -I +guestfs mlguestfs.cmxa prog.ml -o prog

=head1 DESCRIPTION

This manual page documents how to call libguestfs from the OCaml
programming language.  This page just documents the differences from
the C API and gives some examples.  If you are not familiar with using
libguestfs, you also need to read L<guestfs(3)>.

=head2 PROGRAMMING STYLES

There are two different programming styles supported by the OCaml
bindings.  You can use a module style, with each C function mapped to
an OCaml function:

 int guestfs_set_verbose (guestfs_h *g, int flag);

becomes:

 val Guestfs.set_verbose : Guestfs.t -> bool -> unit

Alternately you can use an object-oriented style, calling methods
on the class C<Guestfs.guestfs>:

 method set_verbose : bool -> unit

The object-oriented style is usually briefer, and the minor performance
penalty isn't noticable in the general overhead of performing
libguestfs functions.

=head2 CLOSING THE HANDLE

The handle is closed when it is reaped by the garbage collector.
Because libguestfs handles include a lot of state, it is also
possible to close (and hence free) them explicitly by calling
C<Guestfs.close> or the C<#close> method.

=head2 EXCEPTIONS

Errors from libguestfs functions are mapped into the C<Guestfs.Error>
exception.  This has a single parameter which is the error message (a
string).

Calling any function/method on a closed handle raises
C<Guestfs.Handle_closed>.  The single parameter is the name of the
function that you called.

=head1 EXAMPLE 1: CREATE A DISK IMAGE

@EXAMPLE1@

=head1 EXAMPLE 2: INSPECT A VIRTUAL MACHINE DISK IMAGE

@EXAMPLE2@

=head1 SEE ALSO

L<guestfs(3)>,
L<guestfs-examples(3)>,
L<guestfs-perl(3)>,
L<guestfs-python(3)>,
L<guestfs-ruby(3)>,
L<http://libguestfs.org/>,
L<http://caml.inria.fr/>.

=head1 AUTHORS

Richard W.M. Jones (C<rjones at redhat dot com>)

=head1 COPYRIGHT

Copyright (C) 2010 Red Hat Inc. L<http://libguestfs.org/>

The examples in this manual page may be freely copied, modified and
distributed without any restrictions.

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