=head1 NAME

nbd_aio_connect_command - connect to the NBD server

=head1 SYNOPSIS

 #include <libnbd.h>

 int nbd_aio_connect_command (
       struct nbd_handle *h, char **argv
     );

=head1 DESCRIPTION

Run the command as a subprocess and begin connecting to it over
stdin/stdout.  Parameters behave as documented in
L<nbd_connect_command(3)>.


You can check if the connection attempt is still underway by
calling L<nbd_aio_is_connecting(3)>.  If L<nbd_set_opt_mode(3)>
is enabled, the connection is ready for manual option negotiation
once L<nbd_aio_is_negotiating(3)> returns true; otherwise, the
connection attempt will include the NBD handshake, and is ready
for use once L<nbd_aio_is_ready(3)> returns true.

=head1 RETURN VALUE

If the call is successful the function returns C<0>.

=head1 ERRORS

On error C<-1> is returned.

Refer to L<libnbd(3)/ERROR HANDLING>
for how to get further details of the error.

The following parameters must not be NULL: C<h>, C<argv>.
For more information see L<libnbd(3)/Non-NULL parameters>.

=head1 HANDLE STATE

nbd_aio_connect_command
can be called when the handle is in the following state:

 ┌─────────────────────────────────────┬─────────────────────────┐
 │ Handle created, before connecting   │ ✅ allowed              │
 │ Connecting                          │ ❌ error                │
 │ Connecting & handshaking (opt_mode) │ ❌ error                │
 │ Connected to the server             │ ❌ error                │
 │ Connection shut down                │ ❌ error                │
 │ Handle dead                         │ ❌ error                │
 └─────────────────────────────────────┴─────────────────────────┘

=head1 VERSION

This function first appeared in libnbd 1.0.

If you need to test if this function is available at compile time
check if the following macro is defined:

 #define LIBNBD_HAVE_NBD_AIO_CONNECT_COMMAND 1

=head1 SEE ALSO

L<nbd_aio_is_connecting(3)>,
L<nbd_aio_is_negotiating(3)>,
L<nbd_aio_is_ready(3)>,
L<nbd_connect_command(3)>,
L<nbd_create(3)>,
L<nbd_set_opt_mode(3)>,
L<libnbd(3)>.

=head1 AUTHORS

Eric Blake

Richard W.M. Jones

=head1 COPYRIGHT

Copyright Red Hat
