--email::
Show the email address of each author.
---format[='<format>']::
+--format[=<format>]::
Instead of the commit subject, use some other information to
describe each commit. '<format>' can be any string accepted
by the `--format` option of 'git log', such as '{asterisk} [%h] %s'.
---pretty[='<format>']::
---format='<format>'::
+--pretty[=<format>]::
+--format=<format>::
Pretty-print the contents of the commit logs in a given format,
where '<format>' can be one of 'oneline', 'short', 'medium',