Re: [Libguestfs] [PATCH] v2v: -o vdsm should assume data domain at -os path

On Tue, Jan 20, 2015 at 04:25:20PM +0200, Shahar Havivi wrote: > > > + let pos = (String.length os) - 36 in > > > + let mp = String.sub os 0 (pos-1) in > > > + let uuid = String.sub os pos 36 in > > > > What is the significance of 36 here? > the length of uuid. That code above will throw an exception if you pass a too-short -os parameter. How about this, which should be a little bit easier to understand: let mp, uuid = let fields = string_nsplit "/" os in (* ... "data-center" "UUID" *) let fields = List.rev fields in (* "UUID" "data-center" ... *) match fields with | "" :: uuid :: rest (* handles trailing "/" case *) | uuid :: rest when String.length uuid = 36 -> let mp = String.concat "/" (List.rev rest) in mp, uuid | _ -> error (f_"vdsm: invalid -os parameter does not contain a valid UUID: %s") os

Or perhaps something with regexps ... Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org