Re: [PATCH] rtla/cli: Unify and improve handling of invalid option arguments

[Wander Lairson Costa <wander@redhat.com>]

On Thu, Jul 16, 2026 at 04:49:01PM +0200, Tomas Glozar wrote:
> The current handling of invalid command line option arguments is
> inconsistent:
> 
> - opt_llong_callback() treats non-numerical input the same as "-1",
>   which might or might not be rejected later.
> - opt_int_callback() returns -1 on non-numerical input without an error
>   message, which makes parsing fail silently (libsubcmd will
>   automatically print the usage of the option only, no error message).
> - custom callbacks abort command line parsing using fatal(), which
>   displays an error message and exits, without libsubcmd printing the
>   usage.
> 
> Unify this such that all invalid options, regardless of the format,
> print an error message similar to the out of range case:
> 
> Error: --opt: 'value' is not a valid XY
> 
> followed by the usage of the option, e.g.:
> 
> $ rtla timerlat hist --period=1us
>  Error: --period: '1us' is not a valid number
> 
>  Usage: rtla timerlat hist [<options>] [-h|--help]
> 
>     -p, --period <us>     timerlat period in us
> 
> As this is a libsubcmd help path, all option parsing failures now return
> the exit code of 129 (help).
> 
> The unified handling is implemented using a new error message helper,
> opt_err(), which is called from two new CLI-specific parsing functions,
> strtoll_safe() and strtoi_safe(), as well as from custom helpers.
> 
> Option callback tests are updated to cover the new behavior.
> 
> Assisted-by: Claude:claude-opus-4-6
> Signed-off-by: Tomas Glozar <tglozar@redhat.com>

Reviewed-by: Wander Lairson Costa <wander@redhat.com>