Multiple g_spawn_async_with_pipes

[Neil Hodge <neh attbi com>]

All:

I have the following basic setup:

if (g_spawn_async_with_pipes (dir, argv, NULL,
                      G_SPAWN_FILE_AND_ARGV_ZERO,
                      NULL,
                      NULL,
                      &child_pid, NULL, &pout, &perr,
                      &err)) 
{
        channel = g_io_channel_unix_new (pout);
        g_io_add_watch (channel, G_IO_IN | G_IO_HUP | G_IO_ERR |
                G_IO_NVAL, io_dialog, buffer);
                g_io_channel_unref (channel);
                
        channel = g_io_channel_unix_new (perr);
        g_io_add_watch (channel, G_IO_IN | G_IO_HUP | G_IO_ERR |
                G_IO_NVAL, io_dialog, buffer);
        g_io_channel_unref (channel);
} else {
        [DO ERROR STUFF]
}

static gboolean
io_dialog (GIOChannel * channel, GIOCondition condition, gpointer data)
{
        gchar *text, *text_utf8;
        gint len;
        gssize bytes_written;

        if (condition & G_IO_IN) {
                [PROCESS PIPE]
                return TRUE;
        }
        return FALSE;
}

and it is working fine.  What I need to be able to do is call multiple
processes with g_spawn_async_with_pipes, but have each call block on the
preceding call to g_spawn_async_with_pipes.  It seems like I could place
a second call to g_spawn_async_with_pipes in io_dialog, but if I have
more than two or three of these, this would get way too unwieldy.  Is
there some way to tell one call to g_spawn_async_with_pipes (or any
other command, for that matter) to block (given the pid) on a previous
call to g_spawn_async_with_pipes?  Alternately, I could build up my
command line as follows:

command1; command2

although I am not sure this will work with exec().  Any ideas?  Thanks.

Neil