+dnl Could use these to know if we need to provide a prototype
+dnl AC_CHECK_DECLS(fdatasync, [], [], [#include <unistd.h>])
+
+dnl solaris has fdatasync in the librt
+
+AC_CHECK_FUNC(fdatasync, [], AC_CHECK_LIB(rt, fdatasync, [LIBS="${LIBS} -lrt"],[]))
+
+