New plugin ready: tagcopy

i’ve just finished up a rough working version of a plugin that allows you to copy the data from one tag to another. the github repo is here:

there are example configs for all options in the config_examples folder. here are a couple usage examples:

# example: always copy the contents of the label tag to the composer tag
# (useful for iTunes libraries that don't display the label tag)
tagcopy:
  copy_tags: composer=label

# example: conditionally copy the contents of the label tag to the composer tag
# only when the composer tag is empty
# only_empty_tags applies to all tag copy definitions, you can't apply on a per-tag basis
tagcopy:
  only_empty_tags: yes
  copy_tags: composer=label

when activated, the plugin will run during an import command. it can also be run on the command line using the tagcopy command or tc abbreviation. example usage: beet tc artist:rush album:rush.

let me know if you have any suggestions for improvement or additions to the config options. i hope someone finds it useful!

for your consideration @pd6 @gregbert