Re: [PATCH bpf-next] bpftool: auto-complete BTF IDs for btf dump

[Quentin Monnet <quentin.monnet@netronome.com>]

2019-05-24 22:38 UTC-0700 ~ Andrii Nakryiko <andriin@fb.com>
> Auto-complete BTF IDs for `btf dump id` sub-command. List of possible BTF
> IDs is scavenged from loaded BPF programs that have associated BTFs, as
> there is currently no API in libbpf to fetch list of all BTFs in the
> system.
> 
> Suggested-by: Quentin Monnet <quentin.monnet@netronome.com>
> Signed-off-by: Andrii Nakryiko <andriin@fb.com>
> ---
>  tools/bpf/bpftool/bash-completion/bpftool | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
> index 75c01eafd3a1..9fbc33e93689 100644
> --- a/tools/bpf/bpftool/bash-completion/bpftool
> +++ b/tools/bpf/bpftool/bash-completion/bpftool
> @@ -71,6 +71,13 @@ _bpftool_get_prog_tags()
>          command sed -n 's/.*"tag": "\(.*\)",$/\1/p' )" -- "$cur" ) )
>  }
>  
> +_bpftool_get_btf_ids()
> +{
> +    COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \
> +        command sed -n 's/.*"btf_id": \(.*\),\?$/\1/p' | \
> +        command sort -nu )" -- "$cur" ) )
> +}

Thanks! It works well. It looks like the "sort -nu" is not required,
however? Bash completion on my system seems to run the equivalent of
"sort -u" on the results anyway, ignoring the ordering you made just
before. As I understand this is what completion always does, unless we
pass "-o nosort" to "complete".

E.g. I get the same following output:

	1     1234  191   222   25

When completing with this function:

	_bpftool()
	{
		COMPREPLY+=( $( compgen -W "$( \
			command echo '1 1 1 191 1234 25 222')"))
	}
	complete -F _bpftool bpftool

or with that one:

	_bpftool()
	{
		COMPREPLY+=( $( compgen -W "$( \
			command echo '1 1 1 191 1234 25 222' | \
			command sort -nu )" ) )
	}
	complete -F _bpftool bpftool

Could you double check you have the same thing on your setup, please? If
so we can just remove the "sort -nu".

Quentin