Re: [PATCH 5/7] btrfs-progs: subvol list: implement json format output

[David Sterba <dsterba@suse.cz>]

On Sun, Aug 13, 2023 at 11:45:00AM +0200, Christoph Heiss wrote:
> Implements JSON-formatted output for the `subvolume list` command using
> the `--format json` global option, much like it is implemented for other
> commands.
> 
> Re-uses the `btrfs_list_layout` infrastructure to nicely fit it into the
> existing formatting code.
> 
> A notable difference to the normal, text-based output is that in the
> JSON output, timestamps include the timezone offset as well.
> 
> Signed-off-by: Christoph Heiss <christoph@c8h4.io>
> ---
>  cmds/subvolume-list.c | 91 +++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 88 insertions(+), 3 deletions(-)
> 
> diff --git a/cmds/subvolume-list.c b/cmds/subvolume-list.c
> index 382b0676..be7faca6 100644
> --- a/cmds/subvolume-list.c
> +++ b/cmds/subvolume-list.c
> @@ -35,7 +35,9 @@
>  #include "common/open-utils.h"
>  #include "common/string-utils.h"
>  #include "common/utils.h"
> +#include "common/format-output.h"
>  #include "cmds/commands.h"
> +#include "cmds/subvolume.h"
>  
>  /*
>   * Naming of options:
> @@ -75,6 +77,8 @@ static const char * const cmd_subvolume_list_usage[] = {
>  	OPTLINE("--sort=gen,ogen,rootid,path", "list the subvolume in order of gen, ogen, rootid or path "
>  		"you also can add '+' or '-' in front of each items. "
>  		"(+:ascending, -:descending, ascending default)"),
> +	HELPINFO_INSERT_GLOBALS,
> +	HELPINFO_INSERT_FORMAT,
>  	NULL,
>  };
>  
> @@ -84,7 +88,8 @@ static const char * const cmd_subvolume_list_usage[] = {
>  enum btrfs_list_layout {
>  	BTRFS_LIST_LAYOUT_DEFAULT = 0,
>  	BTRFS_LIST_LAYOUT_TABLE,
> -	BTRFS_LIST_LAYOUT_RAW
> +	BTRFS_LIST_LAYOUT_RAW,
> +	BTRFS_LIST_LAYOUT_JSON

Json should not be a layout, that's relevant only for plain text output.