statvfs()

Wheere can i find documentation for statvfs ?
Any explanation or links would be helpful.

-
Meyers

% man statfs
...
Solaris and POSIX 1003.1-2001 have a system call statvfs that returns a struct statvfs (defined in <sys/statvfs.h>) containing an unsigned long f_fsid. Linux, SunOS, HPUX, 4.4BSD have a system call statfs that returns a struct
statfs (defined in <sys/vfs.h>) containing a fsid_t
f_fsid, where fsid_t is defined as struct { int val[2]; }. The same holds for FreeBSD, except that it uses the include file <sys/mount.h>.
...