Re: [PATCH 1/2] perf tools: Setup pager when printing usage and help

[Namhyung Kim]

On Thu, Oct 22, 2015 at 11:41 PM, Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
> Em Thu, Oct 22, 2015 at 11:28:31PM +0900, Namhyung Kim escreveu:
>> It's annoying to see error or help message when command has many options
>> like in perf record, report or top.  So setup pager when print parser
>> error or help message - it should be OK since no UI is enabled at the
>> parsing time.  The usage_with_options() already disables it by calling
>> exit_browser() anyway.
>
> But then we don't know what went wrong, try:
>
> [acme@zoo linux]$ perf record --all-cpus -g --42 --event cycles 2>&1 | head
>   Error: unknown option `42'
>
>  Usage: perf record [<options>] [<command>]
>     or: perf record [<options>] -- <command> [<options>]
>
>     -e, --event <event>   event selector. use 'perf list' to list
> available events
>         --filter <filter>
>                           event filter
>         --exclude-perf    don't record events from perf itself
>     -p, --pid <pid>       record events on existing process id
> [acme@zoo linux]$
>
> Without this patch I can see what was the option that caused the problem
> (--42 in this case), after the patch I can see only the valid options,
> not the one causing the problem, well, I can see it only if I use the
> same 2>&1 technique above.

Hmm.. some message are printed before calling usage_with_options() so
pager don't know about it.  Will check how to fix this..

Thanks,
Namhyung


>> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
>> Cc: Borislav Petkov <bp@xxxxxxx>
>> Cc: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
>> Cc: Chandler Carruth <chandlerc@xxxxxxxxx>
>> Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
>> Cc: Stephane Eranian <eranian@xxxxxxxxxx>
>> Cc: Wang Nan <wangnan0@xxxxxxxxxx>
>> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
>> ---
>>  tools/perf/util/parse-options.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
>> index 8aa7922397a9..388d385df5ad 100644
>> --- a/tools/perf/util/parse-options.c
>> +++ b/tools/perf/util/parse-options.c
>> @@ -648,6 +648,8 @@ int usage_with_options_internal(const char * const *usagestr,
>>       if (!usagestr)
>>               return PARSE_OPT_HELP;
>>
>> +     setup_pager();
>> +
>>       fprintf(stderr, "\n Usage: %s\n", *usagestr++);
>>       while (*usagestr && **usagestr)
>>               fprintf(stderr, "    or: %s\n", *usagestr++);
>> --
>> 2.6.0
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