Re: [dpdk-dev] [PATCH v3 07/11] eal: add log level help

[Thomas Monjalon <thomas@monjalon.net>]

15/03/2021 11:42, Kinsella, Ray:
> 
> On 15/03/2021 10:31, Bruce Richardson wrote:
> > On Mon, Mar 15, 2021 at 10:19:47AM +0000, Kinsella, Ray wrote:
> >>
> >>
> >> On 12/03/2021 18:17, Thomas Monjalon wrote:
> >>> The option --log-level was not completely described in the usage text,
> >>> and it was difficult to guess the names of the log types and levels.
> >>>
> >>> A new value "help" is accepted after --log-level to give more details
> >>> about the syntax and listing the log types and levels.
> >>>
> >>> The array "levels" used for level name parsing is replaced with
> >>> a (modified) existing function which was used in rte_log_dump().
> >>>
> >>> The new function rte_log_list_types() is exported in the API
> >>> for allowing an application to give this info to the user
> >>> if not exposing the EAL option --log-level.
> >>> The list of log types cannot include all drivers if not linked in the
> >>> application (shared object plugin case).
> >>>
> >>> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> >>> ---
> >>>  lib/librte_eal/common/eal_common_log.c     | 24 +++++++++---
> >>>  lib/librte_eal/common/eal_common_options.c | 44 +++++++++++++++-------
> >>>  lib/librte_eal/common/eal_log.h            |  5 +++
> >>>  lib/librte_eal/include/rte_log.h           | 11 ++++++
> >>>  lib/librte_eal/version.map                 |  3 ++
> >>>  5 files changed, 69 insertions(+), 18 deletions(-)
> >>>
> > <snip>
> >>> @@ -1274,6 +1286,11 @@ eal_parse_log_level(const char *arg)
> >>>  	char *str, *level;
> >>>  	int priority;
> >>>  
> >>> +	if (strcmp(arg, "help") == 0) {
> >>
> >> So I think the convention is to support both "?" and "help".
> >> Qemu does this at least. 
> >>
> > I've seen "/?" used for help on windows binaries, but "-?" not so much in the
> > linux world, where --help (and often -h for short) seem to be the standard.
> > 
> 
> This is slightly different - it is where you are looking to return a list of valid 
> values for a parameter. So for instance in qemu mentioned above 
> 
>  ~ > qemu-system-x86_64 -cpu ? | head -n 10

"?" is a special character.
In my zsh, I need to quote it to avoid globbing parsing,
so I'm not a fan.

I will let you extend the syntax in a separate patch :)