Ausam/doc/man/man5/wtmp.5

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.th WTMP V 31/3/78
.sh NAME
wtmp \*- user login and process termination history
.sh DESCRIPTION
The exact format is described with C structure declarations
in /usr/include/wtmp.h,
but basically there are six types of record in the file,
one each for describing user logon,
user logoff,
asynchronous process termination,
date changes,
super-user accesses,
and system boots.
\*)
.it Wtmp
is maintained by
init(VIII), getty(VIII), and date(I).
None of these programs creates the file,
so if it is removed,
record keeping is turned off.
It can be examined with who(I),
and summarised by ac(VIII).
.sh FILES
/usr/adm/wtmp
.br
/usr/include/wtmp.h
.sh "SEE ALSO"
getty(VIII), init(VIII), ac(VIII), who(I), date(I), utmp(V).