
=head1 НАЗВА

guestfs-lua - How to use libguestfs from Lua

=head1 КОРОТКИЙ ОПИС

 local G = require "guestfs"
 g = G.create ()
 g:add_drive ("test.img", { format = "raw", readonly = true })
 g:launch ()
 devices = g:list_devices ()
 g:close ()

=head1 ОПИС

This manual page documents how to call libguestfs from the Lua 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 REQUIRING THE MODULE

C<require "guestfs"> returns the module, so you have to assign it to a local
variable.  Typical usage is:

 local G = require "guestfs"

(you can use any name you want instead of C<G>, but in the examples in this
man page we always use C<G>).

=head2 OPENING AND CLOSING THE HANDLE

To create a new handle, call:

 g = G.create ()

You can also use the optional arguments:

 g = G.create { environment = 0, close_on_exit = 0 }

to set the flags C<GUESTFS_CREATE_NO_ENVIRONMENT> and/or
C<GUESTFS_CREATE_NO_CLOSE_ON_EXIT>.

The handle will be closed by the garbage collector, but you can also close
it explicitly by doing:

 g:close ()

=head2 ЯК ВИКЛИКАТИ МЕТОДИ

Use the ordinary Lua convention for calling methods on the handle.  For
example:

 g:set_verbose (true)

=head2 ФУНКЦІЇ І ДОДАТКОВІ ПАРАМЕТРИ

For functions that take optional arguments, the first arguments are the
non-optional ones.  The optional final argument is a table supplying the
optional arguments.

 g:add_drive ("test.img")

або:

 g:add_drive ("test.img", { format = "raw", readonly = true })

=head2 64-БІТОВІ ЗНАЧЕННЯ

Currently 64 bit values must be passed as strings, and are returned as
strings.  This is because 32 bit Lua cannot handle 64 bit integers
properly.  We hope to come up with a better solution later.

=head2 ПОМИЛКИ

Most (but not all) errors are converted into objects (ie. tables)
containing the following fields:

=over 4

=item msg

The error message (corresponding to L<guestfs(3)/guestfs_last_error>).

=item code

The C<errno> (corresponding to L<guestfs(3)/guestfs_last_errno>).

=back

These objects also have C<__tostring> functions attached to them so you can
use C<tostring> (or implicit conversion) to convert them into printable
strings.

Note that the library also throws some errors as plain strings.  You may
need to check the type.

=head2 ПОДІЇ

Реєструвати події можна за допомогою викликів C<set_event_callback>:

 eh = g:set_event_callback (cb, "close")

or to register a single callback for multiple events make the second
argument a list:

 eh = g:set_event_callback (cb, { "appliance", "library", "trace" })

A list of all valid event types (strings) is in the global variable
C<G.event_all>.

The callback (C<cb>) is called with the following parameters:

 function cb (g, event, eh, flags, buf, array)
   -- g is the guestfs handle
   -- event is a string which is the name of the event that fired
   -- flags is always zero
   -- buf is the data buffer (eg. log message etc)
   -- array is the array of 64 bit ints (eg. progress bar status etc)
   ...
 end

You can also remove a callback using the event handle (C<eh>) that was
returned when you registered the callback:

 g:delete_event_callback (eh)

=head1 ПРИКЛАД 1. СТВОРЕННЯ ОБРАЗУ ДИСКА

@EXAMPLE1@

=head1 ПРИКЛАД 2. ПЕРЕВІРКА ОБРАЗУ ДИСКА ВІРТУАЛЬНОЇ МАШИНИ

@EXAMPLE2@

=head1 ТАКОЖ ПЕРЕГЛЯНЬТЕ

L<guestfs(3)>, L<guestfs-examples(3)>, L<guestfs-erlang(3)>,
L<guestfs-golang(3)>, L<guestfs-java(3)>, L<guestfs-ocaml(3)>,
L<guestfs-perl(3)>, L<guestfs-python(3)>, L<guestfs-recipes(1)>,
L<guestfs-ruby(3)>, L<http://www.lua.org/>, L<http://libguestfs.org/>.

=head1 АВТОРИ

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

=head1 АВТОРСЬКІ ПРАВА

© Red Hat Inc., 2012

