Re: [PATCH bpf-next 2/2] selftests/bpf: Fix vmtest.sh getopts optstring

[Daniel Müller]

On Tue, Aug 09, 2022 at 11:11:10AM -0600, Daniel Xu wrote:
> Before, you could see the following errors:
> 
> ```
> $ ./vmtest.sh -j
> ./vmtest.sh: option requires an argument -- j
> ./vmtest.sh: line 357: OPTARG: unbound variable
> 
> $ ./vmtest.sh -z
> ./vmtest.sh: illegal option -- z
> ./vmtest.sh: line 357: OPTARG: unbound variable
> ```
> 
> Fix by adding ':' as first character of optstring. Reason is that
> getopts requires ':' as the first character for OPTARG to be set in the
> `?` and `:` error cases.
> 
> Signed-off-by: Daniel Xu <dxu@xxxxxxxxx>
> ---
>  tools/testing/selftests/bpf/vmtest.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/bpf/vmtest.sh b/tools/testing/selftests/bpf/vmtest.sh
> index 976ef7585b33..a29aa05ebb3e 100755
> --- a/tools/testing/selftests/bpf/vmtest.sh
> +++ b/tools/testing/selftests/bpf/vmtest.sh
> @@ -333,7 +333,7 @@ main()
>  	local exit_command="poweroff -f"
>  	local debug_shell="no"
>  
> -	while getopts 'hskid:j:' opt; do
> +	while getopts ':hskid:j:' opt; do
>  		case ${opt} in
>  		i)
>  			update_image="yes"
> -- 
> 2.37.1
> 

I tested with this change and it worked fine for me. One thing to consider
pointing out more clearly in the description is that ':' as the first character
of the optstring switches getopts to silent mode. The desire to run in this mode
seems to have been there all along, as the script takes care of reporting
errors.

Acked-by: Daniel Müller <deso@xxxxxxxxxx>