Re: [PATCH 08/17] hook: add 'run' subcommand

> 
> Hi Emily
> 
> On 05/12/2020 01:45, Emily Shaffer wrote:
> > In order to enable hooks to be run as an external process, by a
> > standalone Git command, or by tools which wrap Git, provide an external
> > means to run all configured hook commands for a given hook event.
> > 
> > For now, the hook commands will run in config order, in series. As
> > alternate ordering or parallelism is supported in the future, we should
> > add knobs to use those to the command line as well.
> > 
> > As with the legacy hook implementation, all stdout generated by hook
> > commands is redirected to stderr. Piping from stdin is not yet
> > supported.
> > 
> > Legacy hooks (those present in $GITDIR/hooks) are run at the end of the
> > execution list. For now, there is no way to disable them.
> > 
> > Users may wish to provide hook commands like 'git config
> > hook.pre-commit.command "~/linter.sh --pre-commit"'. To enable this, the
> > contents of the 'hook.*.command' and 'hookcmd.*.command' strings are
> > first split by space or quotes into an argv_array, then expanded with
> > 'expand_user_path()'.
> 
> I'm a bit confused by this last paragraph, the docs below say we pass the
> string to the shell and that's what the implementation seems to do. If we're
> running a lot of hooks then maybe it would be worth using split_cmdline()
> and expand_user_path() rather than invoking the shell for each hook we run.

> > +static int should_include_hookdir(const char *path, enum hookdir_opt cfg)
> > +{
> > +	struct strbuf prompt = STRBUF_INIT;
> > +	/*
> > +	 * If the path doesn't exist, don't bother adding the empty hook and
> > +	 * don't bother checking the config or prompting the user.
> > +	 */
> > +	if (!path)
> > +		return 0;
> > +
> > +	switch (cfg)
> > +	{
> > +		case hookdir_no:
> 
> Style nit: we normally use uppercase for constants and enums.

> 
> > +			return 0;
> > +		case hookdir_unknown:
> > +			fprintf(stderr,
> > +				_("Unrecognized value for 'hook.runHookDir'. "
> > +				  "Is there a typo? "));
> 
> What happens at the moment if core.hooksPath does not exist?