Re: [PATCH v3] rev-list: teach --no-object-names to enable piping

[Junio C Hamano <gitster@pobox.com>]

Emily Shaffer <emilyshaffer@google.com> writes:

> Allow easier parsing by cat-file by giving rev-list an option to print
> only the OID of a non-commit object without any additional information.
> This is a short-term shim; later on, rev-list should be taught how to
> print the types of objects it finds in a format similar to cat-file's.
>
> Before this commit, the output from rev-list needed to be massaged
> before being piped to cat-file, like so:
>
>   git rev-list --objects HEAD | cut -f 1 -d ' ' \
>     | git cat-file --batch-check

Write this with '|' at the end of the first line; that way the shell
knows you haven't finished your sentence without any backslash.

> diff --git a/builtin/rev-list.c b/builtin/rev-list.c
> index 660172b014..7e2598fd22 100644
> --- a/builtin/rev-list.c
> +++ b/builtin/rev-list.c
> @@ -49,6 +49,7 @@ static const char rev_list_usage[] =
>  "    --objects | --objects-edge\n"
>  "    --unpacked\n"
>  "    --header | --pretty\n"
> +"    --no-object-names\n"

Ideally, this should be "--[no-]object-names", i.e. --object-names
which may be the default when using --objects could be tweaked with
--no-object-names and then again turned on with a --object-names
later on the command line, following the usual "last one wins".

> @@ -75,6 +76,9 @@ enum missing_action {
>  };
>  static enum missing_action arg_missing_action;
>  
> +/* display only the oid of each object encountered */
> +static int arg_no_object_names;

And this would become

    static int show_object_names = 1;

that can be turned off via --no-object-names (and --object-names
would flip it on).  It would reduce the double negation brain
twister, hopefully.