$ cat include/net-snmp/net-snmp-config.h| grep -i statfs
/* Define to 1 if you have the `statfs' function. */
#define HAVE_STATFS 1
/* Define to 1 if `f_favail' is a member of `struct statfs'. */
/* #undef HAVE_STRUCT_STATFS_F_FAVAIL */
/* Define to 1 if `f_ffree' is a member of `struct statfs'. */
#define HAVE_STRUCT_STATFS_F_FFREE 1
/* Define to 1 if `f_files' is a member of `struct statfs'. */
#define HAVE_STRUCT_STATFS_F_FILES 1
/* Define to 1 if `f_flags' is a member of `struct statfs'. */
/* #undef HAVE_STRUCT_STATFS_F_FLAGS */
/* Define to 1 if `f_frsize' is a member of `struct statfs'. */
#define HAVE_STRUCT_STATFS_F_FRSIZE 1
/* Define to 1 if you have the <sys/statfs.h> header file. */
#define HAVE_SYS_STATFS_H 1
/* Define if statfs takes 2 args and the second argument has type struct
/* #undef STAT_STATFS_FS_DATA */
$