Libguestfs - Mar 2017 - Re: [PATCH 4/5] dib: require a Python interpreter

On Wed, Mar 22, 2017 at 11:19:49AM +0100, Pino Toscano
wrote:
>    if elements = [] && machine_readable then (
> @@ -246,6 +252,19 @@ read the man page virt-dib(1).
>    if elements = [] then
>      error (f_"at least one distribution root element must be
specified");
>  
> +  let python > +    match python with
> +    | Some exe ->
> +      let p > +        if Filename.is_relative exe then
IIUC what you mean here is "the 'exe' filename doesn't contain
any slashes"?  That isn't what is written above.
> +          get_required_tool exe
> +        else (
> +          Unix.access exe [Unix.X_OK];
> +          exe
> +        ) in
> +      Some p
> +    | None -> None in
Rich.

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On Wednesday, 22 March 2017 16:56:57 CET Richard W.M. Jones
wrote:
> On Wed, Mar 22, 2017 at 11:19:49AM +0100, Pino Toscano wrote:
> >    if elements = [] && machine_readable then (
> > @@ -246,6 +252,19 @@ read the man page virt-dib(1).
> >    if elements = [] then
> >      error (f_"at least one distribution root element must be
specified");
> >  
> > +  let python > > +    match python with
> > +    | Some exe ->
> > +      let p > > +        if Filename.is_relative exe then
> 
> IIUC what you mean here is "the 'exe' filename doesn't
contain
> any slashes"?  That isn't what is written above.
Yes, sort of.  What about something like:

  let p     try
      ignore (String.find exe Filename.dir_sep);
      Unix.access exe [Unix.X_OK];
      exe
    with
    | Not_found ->
      get_required_tool exe in

Thanks,
-- 
Pino Toscano

On Wed, Mar 22, 2017 at 06:03:07PM +0100, Pino Toscano
wrote:
> On Wednesday, 22 March 2017 16:56:57 CET Richard W.M. Jones wrote:
> > On Wed, Mar 22, 2017 at 11:19:49AM +0100, Pino Toscano wrote:
> > >    if elements = [] && machine_readable then (
> > > @@ -246,6 +252,19 @@ read the man page virt-dib(1).
> > >    if elements = [] then
> > >      error (f_"at least one distribution root element must
be specified");
> > >  
> > > +  let python > > > +    match python with
> > > +    | Some exe ->
> > > +      let p > > > +        if Filename.is_relative exe
then
> > 
> > IIUC what you mean here is "the 'exe' filename
doesn't contain
> > any slashes"?  That isn't what is written above.
> 
> Yes, sort of.  What about something like:
> 
>   let p >     try
>       ignore (String.find exe Filename.dir_sep);
>       Unix.access exe [Unix.X_OK];
>       exe
>     with
>     | Not_found ->
>       get_required_tool exe in
The String.find function in mllib/ returns -1 for not found.  I think
it never throws an exception.  But in general yes that's a better
approach.

Rich.

-- 
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