progs-output-format.txt

Progs with a better output format
---------------------------------

Allow a machine readable output for various commands in progs.

- one global option to specify the output type
- global options to affect the type and more specific formats, eg. if the
  header should be printed or only the raw structured data
- potential output format: json, xml, plain text, yaml
  - preferred: json, plain
- options might have specific formats for columns, sorting etc
- consistency is important
- make way for future changes, do not get too much into specifications though

- not all commands will be aple to print that, only best effort

Interface:

$ btrfs --format=json subvolume list /

{
	version: 1,
	header: {
		{ name: "id", type: integer},
		{ name: "path", type: string}
	},
	list: {
		{ 256, "subv1"},
		{ 257, "subv2"}
	},
	footer {... whatever },
	summary {... whatever}
}

- structured lists in case the format is one-line, unique to the command
- key-value, value might be term or structured data