Overflowing wtmp

[WU SHI-KUEI]

In article <705 at camco.Celestial.COM> bill at camco.Celestial.COM (Bill Campbell) writes:
>In <92 at tdatirv.UUCP> sarima at tdatirv.UUCP (Stanley Friesen) writes:
>
>
>>OK, now for a silly question.
	Not at all silly
>
>>I am the adminsitrator of a SCO Xenix/286 system, and the system administrator
>>documentation is rather limited.
>
>
>>I have found that my wtmp file tends to grow without bound.
>>This is annoying.  Is there any clean way to trim it, short of the rather
>>crude 'cat /dev/null > /etc/wtmp' approach.  (I *do* know about cron,
>>I just need to know what to put in it).
>>-- 
>>---------------
>>uunet!tdatirv!sarima				(Stanley Friesen)
>
>This usually is caused by a flakey terminal connection, bad
>ground or some such.  ......

If the complaint were about '/etc/utmp', Bill Campbell's analysis might
well be correct.  However, '/etc/wtmp' will grow forever on every system,
and

	cat /dev/null > /etc/wtmp

is as good as any other.  I suppose one could read the whole file, close
it, then re-open it and write only the last N structures as shown in
Section 4 back.  But why bother??