add option metaflac --show-all-tags

[harridu]

Signed-off-by: Harald Dunkel [email protected] I would like to suggest to add an option --show-all-tags to metaflac, listing all tags found in the header. The functionality is already in the code. This patch adds just a command line option to use it.

Sample:

% metaflac --show-all-tags Kraftwerk/Autobahn/01_Autobahn.flac 
ARTIST=Kraftwerk
TRACKNUMBER=01
ALBUM=Autobahn
TITLE=Autobahn
GENRE=Electronic
DATE=1974

[ktmf01]

Is there any difference to metaflac --export-tags-to=- or was that option unknown to you?

[harridu]

I heard about this before, but it is not intuitive to use and hard to find in the man page. There are options --remove-tag and --remove-all-tags, but next to --show-tag there is no --show-all-tags.

[ktmf01]

I'd rather not duplicate functionality. I see two ways to do this.

1. drop most of this patch, and simply add text to the man page for option --show-tag suggesting to use --export-tags-to=- to show all tags
2. minimize this patch by making --show-all-tags an alias for --export-tags-to=-, implementing this alias in options.c

[ktmf01]

@harridu Are you still planning to do anything with this PR?

[ktmf01]

I added a commit simplifying this PR.

Note to self: I still need to add a test for --export-tags-to=- and --show-all-tags, but that would conflict with #504, so I should probably wait with that until that one is merged.