It's useful and efficient to be able to get the size of the contents directly without having to pipe through `wc -c`. Also the result of the following: `git for-each-ref --format='%(contents)' refs/heads/my-branch | wc -c` is off by one as `git for-each-ref` appends a newline character after the contents, which can be seen by comparing its output with the output from `git cat-file`. As with %(contents), %(contents:size) is silently ignored, if a ref points to something other than a commit or a tag: ``` $ git update-ref refs/mytrees/first HEAD^{tree} $ git for-each-ref --format='%(contents)' refs/mytrees/first $ git for-each-ref --format='%(contents:size)' refs/mytrees/first ``` Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>