[PATCH bpf-next] samples/bpf: xdp_monitor, accept short options

[PATCH bpf-next] samples/bpf: xdp_monitor, accept short options

[Prashant Bhole]

updated optstring accept short options

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
---
 samples/bpf/xdp_monitor_user.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c
index 894bc64c2cac..668511c77aaf 100644
--- a/samples/bpf/xdp_monitor_user.c
+++ b/samples/bpf/xdp_monitor_user.c
@@ -594,7 +594,7 @@ int main(int argc, char **argv)
 	snprintf(bpf_obj_file, sizeof(bpf_obj_file), "%s_kern.o", argv[0]);
 
 	/* Parse commands line args */
-	while ((opt = getopt_long(argc, argv, "h",
+	while ((opt = getopt_long(argc, argv, "hDSs:",
 				  long_options, &longindex)) != -1) {
 		switch (opt) {
 		case 'D':
-- 
2.13.6

Re: [PATCH bpf-next] samples/bpf: xdp_monitor, accept short options

[Jesper Dangaard Brouer]

On Fri, 11 May 2018 10:37:51 +0900
Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> wrote:

> updated optstring accept short options
> 
> Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
> ---
>  samples/bpf/xdp_monitor_user.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c
> index 894bc64c2cac..668511c77aaf 100644
> --- a/samples/bpf/xdp_monitor_user.c
> +++ b/samples/bpf/xdp_monitor_user.c
> @@ -594,7 +594,7 @@ int main(int argc, char **argv)
>  	snprintf(bpf_obj_file, sizeof(bpf_obj_file), "%s_kern.o", argv[0]);
>  
>  	/* Parse commands line args */
> -	while ((opt = getopt_long(argc, argv, "h",
> +	while ((opt = getopt_long(argc, argv, "hDSs:",
>  				  long_options, &longindex)) != -1) {
>  		switch (opt) {
>  		case 'D':

It was actually on purpose that I didn't add the short options,
in-order to force people use those "self-documenting" long-options when
they show the usage on public mailing lists or in blog-posts.

If you want these short options, you also have to correct the "usage"
function that state these are "internal" short-options.

Notice the long options parsing done by getopt_long() allow you to only
specify part of the string.  Al-through, I can see --s is ambiguous.

$ sudo ./xdp_monitor --s
./xdp_monitor: option '--s' is ambiguous; possibilities: '--stats' '--sec'

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer

Re: [PATCH bpf-next] samples/bpf: xdp_monitor, accept short options

[Prashant Bhole]

On 5/12/2018 1:31 AM, Jesper Dangaard Brouer wrote:
> On Fri, 11 May 2018 10:37:51 +0900
> Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp> wrote:
> 
>> updated optstring accept short options
>>
>> Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
>> ---
>>   samples/bpf/xdp_monitor_user.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/samples/bpf/xdp_monitor_user.c b/samples/bpf/xdp_monitor_user.c
>> index 894bc64c2cac..668511c77aaf 100644
>> --- a/samples/bpf/xdp_monitor_user.c
>> +++ b/samples/bpf/xdp_monitor_user.c
>> @@ -594,7 +594,7 @@ int main(int argc, char **argv)
>>   	snprintf(bpf_obj_file, sizeof(bpf_obj_file), "%s_kern.o", argv[0]);
>>   
>>   	/* Parse commands line args */
>> -	while ((opt = getopt_long(argc, argv, "h",
>> +	while ((opt = getopt_long(argc, argv, "hDSs:",
>>   				  long_options, &longindex)) != -1) {
>>   		switch (opt) {
>>   		case 'D':
> 
> It was actually on purpose that I didn't add the short options,
> in-order to force people use those "self-documenting" long-options when
> they show the usage on public mailing lists or in blog-posts.

Got it.

> 
> If you want these short options, you also have to correct the "usage"
> function that state these are "internal" short-options.

I am submitting v2 with "usage" updated, because with usability point of 
view it is nice to have short options. Thanks.

-Prashant

> 
> Notice the long options parsing done by getopt_long() allow you to only
> specify part of the string.  Al-through, I can see --s is ambiguous.
> 
> $ sudo ./xdp_monitor --s
> ./xdp_monitor: option '--s' is ambiguous; possibilities: '--stats' '--sec'