This supercedes the series at id:1396056046-2247-1-git-send-email-david@tethera.net Since the last version posted there, I did the latest round of style fixes from Tomi, and modified the API of gz_readline to return a status code. In the future I'd like to unify the HEX_* codes with the new enum defined in util.h. It might also be good to document util.h a bit.