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

["Kinsella, Ray" <mdr@ashroe.eu>]

On 15/03/2021 15:59, Stephen Hemminger wrote:
> On Mon, 15 Mar 2021 11:52:13 +0100
> Thomas Monjalon <thomas@monjalon.net> wrote:
> 
>> 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 :)
>>
>>
> 
> Also '?' is used by getopt to match unknown option. So qemu might just be
> doing that as unintended side effect of any unknown option
> 

for other unknowns it explicitly complains ... 

~ > qemu-system-x86_64 -cpu unknown
Unable to init server: Could not connect: Connection refused
qemu-system-x86_64: unable to find CPU model 'unknown