[PATCH V2] tools/perf/tests: Fix string substitutions in build id test

[Athira Rajeev]

> On 19-Jan-2023, at 5:32 PM, David Laight <David.Laight at ACULAB.COM> wrote:
> 
> From: Athira Rajeev
>> Sent: 19 January 2023 11:31
> ...
>> diff --git a/tools/perf/tests/shell/buildid.sh b/tools/perf/tests/shell/buildid.sh
>> index aaf851108ca3..43e43e131be7 100755
>> --- a/tools/perf/tests/shell/buildid.sh
>> +++ b/tools/perf/tests/shell/buildid.sh
>> @@ -66,7 +66,7 @@ check()
>> 	esac
>> 	echo "build id: ${id}"
>> 
>> -	link=${build_id_dir}/.build-id/${id:0:2}/${id:2}
>> +	link=${build_id_dir}/.build-id/$(echo ${id}|cut -c 1-2)/$(echo ${id}|cut -c 3-)
>> 	echo "link: ${link}"
> 
> That is horrid, why not just use valid shell substitutions, eg:
> 	id_file=${id#??}
> 	id_dir=${id%$id_file}
> 	link=$build_id_dir/.build-id/$id_dir/$id_file
> 
> ...
>> -	check ${@: -1}
>> +	check $last
> 
> Since this is the end of the shell function you can avoid the eval
> by doing:
> 	shift $(($# - 1))
> 	check $1
> or maybe:
> 	args="$*"
> 	check ${args##* }
> 
> Those should be ok in all posix shells.
> 
> 	David
> 
Hi David,

Thanks for the review. I will post a V3 addressing these changes.

Athira
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)