*BSD News Article 44140


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From: bugs@news.win.net (Mark Hittinger)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: [Q] username length limit: getting around it
Date: 16 May 1995 23:40:24 -0400
Organization: Win.Net Communications, Inc.
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References: <3p0av2$edf@decaxp.harvard.edu>
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itsymbal@scws36.harvard.edu (Sir Ilya) writes:
>There seems to be a limit on how long a username can be.
>For example, I can adduser webadmin and it works just fine, but not with 
>a name like webmaster. Is there a way to get around this?

In /usr/include/utmp.h set UT_NAMESIZE to 10.  In the kernel there is
a companion parameter called MAX_LOGNAME (or something) in param.h.

The kernel's user name length limit is 11 chars + null byte.  The
default utmp.h size is 8.

I reset UT_NAMESIZE to 10 on my boxes and recompiled the various 
utilities.  One module you might forget to recomple is xterm. :-)

Shutdown/reboot in single user mode and remove the utmp file.  Then
allow the system to come up and you are there.

This seems to work great except for a user such as "1iamalong1".  The
sendmail doesn't seem to like usernames with a digit as the first character.

I have tried to get the core team to adopt UT_NAMESIZE=10 so that I wouldn't
have to keep adjusting it - but so far they like char8 :-).

When I tried to set the kernel for max_logname up to 16 ect bizarre things
happened so I backed off to 10.

Regards,

Mark Hittinger
bugs@win.net
-- 
"This is going to cause more confusion than a mouse in a burlesque show." -
							Foghorn Leghorn.