Subject: Re: misc/2668: login-names >8 chars make no fun
To: Chris G Demetriou <Chris_G_Demetriou@ux2.sp.cs.cmu.edu>
From: matthew green <mrg@eterna.com.au>
List: current-users
Date: 08/16/1996 11:33:48
   Either you change the binary format of utmp and wtmp, or you don't.
   
   If you don't, you aren't recording all of the login name.
   If you do, you break binary compatibility.

except if you take the idea that SVR4 used (creating another file,
with much larger username/hostname/etc, but still fixed size
entries, and then having the routines to update this file also
maintain the utmp/wtmp files) and learn from their mistakes and
come up with a *real* solution, that just happens to also maintain
backwards compatibility.

you could also "break" binary compatibility but retain the ability
to read the old format with updated tools that do both.