Re: [PATCH 3/6] hook: add --list mode

> Teach 'git hook --list <hookname>', which checks the known configs in
> order to create an ordered list of hooks to run on a given hook event.
> 
> The hook config format is "hook.<hookname> = <order>:<path-to-hook>".
> This paves the way for multiple hook support; hooks should be run in the
> order specified by the user in the config, and in the case of an order
> number collision, configuration order should be used (e.g. global hook
> 004 will run before repo hook 004).
> 
> For example:
> 
>   $ grep -A2 "\[hook\]" ~/.gitconfig
>   [hook]
>           pre-commit = 001:~/test.sh
>           pre-commit = 999:~/baz.sh
> 
>   $ grep -A1 "\[hook\]" ~/git/.git/config
>   [hook]
>           pre-commit = 900:~/bar.sh
> 
>   $ ./bin-wrappers/git hook --list pre-commit
>   001     global  ~/test.sh
>   900     repo    ~/bar.sh
>   999     global  ~/baz.sh
> 
> Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
> ---
>  Documentation/git-hook.txt    | 17 +++++++-
>  Makefile                      |  1 +
>  builtin/hook.c                | 54 ++++++++++++++++++++++-
>  hook.c                        | 81 +++++++++++++++++++++++++++++++++++
>  hook.h                        | 14 ++++++
>  t/t1360-config-based-hooks.sh | 43 ++++++++++++++++++-
>  6 files changed, 206 insertions(+), 4 deletions(-)
>  create mode 100644 hook.c
>  create mode 100644 hook.h
> 
> diff --git a/Documentation/git-hook.txt b/Documentation/git-hook.txt
> index 2d50c414cc..a141884239 100644
> --- a/Documentation/git-hook.txt
> +++ b/Documentation/git-hook.txt
> @@ -8,12 +8,27 @@ git-hook - Manage configured hooks
>  SYNOPSIS
>  --------
>  [verse]
> -'git hook'
> +'git hook' -l | --list <hook-name>
>  
>  DESCRIPTION
>  -----------
>  You can list, add, and modify hooks with this command.
>  
> +This command parses the default configuration files for lines which look like
> +"hook.<hook-name> = <order number>:<hook command>", e.g. "hook.pre-commit =
> +010:/path/to/script.sh". In this way, multiple scripts can be run during a
> +single hook. Hooks are sorted in ascending order by order number; in the event
> +of an order number conflict, they are sorted in configuration order.
> +
> +OPTIONS
> +-------
> +
> +-l::
> +--list::
> +	List the hooks which have been configured for <hook-name>. Hooks appear
> +	in the order they should be run. Output of this command follows the
> +	format '<order number> <origin config> <hook command>'.
> +
>  GIT
>  ---
>  Part of the linkgit:git[1] suite

> diff --git a/builtin/hook.c b/builtin/hook.c
> index b2bbc84d4d..8261302b27 100644
> --- a/builtin/hook.c
> +++ b/builtin/hook.c
> @@ -1,21 +1,73 @@
>  #include "cache.h"
>  
>  #include "builtin.h"
> +#include "config.h"
> +#include "hook.h"
>  #include "parse-options.h"
> +#include "strbuf.h"
>  
>  static const char * const builtin_hook_usage[] = {
> -	N_("git hook"),
> +	N_("git hook --list <hookname>"),
>  	NULL
>  };
>  
> +enum hook_command {
> +	HOOK_NO_COMMAND = 0,
> +	HOOK_LIST,
> +};
> +
> +static int print_hook_list(const struct strbuf *hookname)
> +{
> +	struct list_head *head, *pos;
> +	struct hook *item;
> +
> +	head = hook_list(hookname);
> +
> +	list_for_each(pos, head) {
> +		item = list_entry(pos, struct hook, list);
> +		if (item)
> +			printf("%.3d\t%s\t%s\n", item->order,
> +			       config_scope_to_string(item->origin),
> +			       item->command.buf);
> +	}
> +
> +	return 0;
> +}
> +
>  int cmd_hook(int argc, const char **argv, const char *prefix)
>  {
> +	enum hook_command command = 0;
> +	struct strbuf hookname = STRBUF_INIT;
> +
>  	struct option builtin_hook_options[] = {
> +		OPT_CMDMODE('l', "list", &command,
> +			    N_("list scripts which will be run for <hookname>"),
> +			    HOOK_LIST),