First, seconding what others are saying. This is not the right list
for your problem if you go into the low-level APIs.
The main difference between tiger and leopard's who source is the
use of utmp and utmpx. utmp has been deprecated on leopard. leopard
uses utmpx to retrieve currently logging in users. utmp uses at
tiger is buggy?
It's just limited. It's pretty easy to spot the difference in this
regard, no guessing needed: the size of the ut_name member of the utmp
struct is defined as 8 bytes. In the utmpx struct, however, you'll
find that the size of the ut_user member is defined as 256 bytes. The
old struct could only hold the first eight characters of the short
name, while the one preferred under Leopard can hold very long short
names.
