why doesn't "tail -f" use select or poll?

[Joshua Haberman]

Is there any reason why "tail -f" doesn't use select or poll, instead  
of sleep?

For the case where you are following a filename instead of an fd I  
realize this isn't possible.  But for the more common case, where you  
*are* following a fd, select would make it so you immediately see any  
output, instead of having to wait for the next sleep interval.  It  
would make the program a little nicer to use.

Maybe some systems don't have select or poll, but for the ones that  
do, it seems like a clear win.

What do you think?

Josh