if (header[4] != _GRAS_header[4])
THROW2(mismatch_error,0,"GRAS protocol mismatch (got %d, use %d)",
(int)header[4], (int)_GRAS_header[4]);
r_arch = (int)header[5];
if (header[4] != _GRAS_header[4])
THROW2(mismatch_error,0,"GRAS protocol mismatch (got %d, use %d)",
(int)header[4], (int)_GRAS_header[4]);
r_arch = (int)header[5];