$ tc.who.c
$set 26 
1 cannot stat %s.  Please "unset watch".\n
2 %s cannot be opened.  Please "unset watch".\n
3 BUG! last element is not whotail!\n
4 backward: 
5 BUG! first element is not whohead!\n
6 new: %s/%s\n
7 %n has %a %l from %m.
8 %n has %a %l.
9 logged on
10 logged off
11 replaced %s on
12 local