rb_io_fread      718 io.c           	n = rb_io_fread(RSTRING(str)->ptr+bytes, siz-bytes, fptr->f);
rb_io_fread      763 io.c               n = rb_io_fread(RSTRING(str)->ptr, len, fptr->f);
rb_io_fread      727 marshal.c      	if (rb_io_fread(RSTRING(str)->ptr, len, arg->fp) != len) {