get email addr from username (was: Ad-hoc notes from the "pending patches" BOF at the GNU tools cauldron.)

[Dimitrios Apostolou]

Hello,

I'm trying to write a small script that shows emails addresses for all 
committers of last year, for all files a patch touches. In the commit logs 
however all committers are referred to by username, and grepping the 
MAINTAINERS files sometimes doesn't bring up any email address (e.g. grep 
for jsm28).

Any idea how I can get email address for a username?


Thanks,
Dimitris