fastest_cvsup 是一支用perl寫成的script,
配合Time::HiRes這個模組,
用千分之一秒之精確來測量反應速度最快的server.

fastest_cvsup – finds fastest CVSup server

Usage: ./fastest_cvsup [-h] [-q|Q] [-r] -c (country codes|local|all)
Where: -h prints this screen
-q quiet mode, only outputs fastest server
-Q very quiet mode, no progress meter
-r uses remote server list from FreeBSD Handbook
-c aa,bb,cc queries servers in countries aa,bb,cc
local queries servers set as local in the script
all queries all FreeBSD servers

See the man page, fastest_cvsup(7), for more details.