Subject: Re: utmp file format change
To: None <>
From: Simon Burge <>
List: tech-userlevel
Date: 08/22/2001 23:44:16
Jun-ichiro itojun Hagino wrote:

> 	I really would love to see utmp/wtmp file format to be updated before
> 	1.6, so that it would be able to accomodate full IPv6 numeric address
> 	as well as longer host names.
> [ ... ]
> 	- Solaris uses struct utmpx, instead of utmp.  which does not look very
> 	  good to me.
> 	- openbsd bumped UT_xx (file format changed), with no backward
> 	  compatibility supplied for older log files.
> [ ... ]
> 	the approach I like the best is the openbsd one, with a bit of clever
> 	backward compat code in last(1) and other tools.  any comments?

Binary compatibility is a problem.  Every writer of utmp/wtmp would need
to be updated at the same time (including any packages - ssh-type and
xterm-type packages come to mind) other file corruption will be a real

Doesn't the Solaris utmpx use a daemon for updates to the file, or am I
misremembering?  For someone who hasn't really looked at what they did,
what is wrong with their solution to this problem?

Perhaps a new filename altogether ( /var/log/wtmpx :-), with a flag for
last to scan both the old and new files at the same time when it does
it's backwards scan.  That way old applications won't corrupt the new

Simon Burge                            <>
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