rwpipe_read_number  171 vhook/ppm.c            *width = rwpipe_read_number( rw );
rwpipe_read_number  172 vhook/ppm.c            *height = rwpipe_read_number( rw );
rwpipe_read_number  173 vhook/ppm.c            max = rwpipe_read_number( rw );