Just to make sure that there's not too much confusion on wtmp vs wtmpx
and utmp vs utmpx, this is how it works;
wtmp - old SYSV style wtmp files (see utmp.h), keeps record
of all log in/log outs
wtmpx - eXtended version of wtmp: adds hostname and extends other
records (32 char user vs 8 char user, 32 bit pid vs 16 bit
pid) See utmpx.h
wtmp and wtmpx record the same information in parallel (the routines
that update them update both) wtmp if for backward compatibility.
Wtmp will go away.
Casper