Re: [PATCH v3 3/5] x86: Add usage() to print out usage message

[Fouad Hilly <fouad.hilly@xxxxxxxxx>]

On Mon, May 6, 2024 at 9:20 AM Jan Beulich <jbeulich@xxxxxxxx> wrote:
>
> On 30.04.2024 14:47, Fouad Hilly wrote:
> > Refactor xen-ucode tool by adding usage() to handle usage\help messages.
> > As we add more command options this will keep help\usage messages in a 
> > common block.
> > Only generic error message is printed to stderr. usage and show_curr_cpu 
> > are printed to stdout.
> >
> > Signed-off-by: Fouad Hilly <fouad.hilly@xxxxxxxxx>
> > ---
> > [v3]
> > 1- Reverted usage message.
> > 2- Utilized usage().
> >
> > [v2]
> > 1- Improved message description.
> > 2- Fixed formatting and indentation.
> > 3- Error message to print to stderr.
>
> Already on v2 I pointed out that this change wasn't really done. And now,
> in v3, ...
>
In V4 all printing within ext_err path will be printed to stder

> >  tools/misc/xen-ucode.c | 12 +++++++++---
> >  1 file changed, 9 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/misc/xen-ucode.c b/tools/misc/xen-ucode.c
> > index c6ae6498d659..005bf85b6551 100644
> > --- a/tools/misc/xen-ucode.c
> > +++ b/tools/misc/xen-ucode.c
> > @@ -17,6 +17,13 @@ static xc_interface *xch;
> >  static const char intel_id[] = "GenuineIntel";
> >  static const char   amd_id[] = "AuthenticAMD";
> >
> > +static void usage(const char *name)
> > +{
> > +    printf("%s: Xen microcode updating tool\n"
> > +           "Usage: %s [<microcode file> | show-cpu-info]\n",
> > +           name, name);
> > +}
>
> ... you're still unconditionally printing to stdout, when ...
>
> >  static void show_curr_cpu(FILE *f)
> >  {
> >      int ret;
> > @@ -89,9 +96,8 @@ int main(int argc, char *argv[])
> >      if ( argc < 2 )
> >      {
> >          fprintf(stderr,
> > -                "xen-ucode: Xen microcode updating tool\n"
> > -                "Usage: %s [<microcode file> | show-cpu-info]\n", argv[0]);
> > -        show_curr_cpu(stderr);
> > +                "%s: unable to process command line arguments\n", argv[0]);
> > +        usage(argv[0]);
> >          exit(2);
> >      }
>
> ... originally the usage message (correctly) went to stderr in this case.
> It ought to go to stdout only in response to something like a --help
> command line option.
>
> Jan