On Fri, 13 Jul 2018 15:23:30 -0700, Stephen Hemminger wrote: > > > I prefer to not use "printf(fp," and use print_string(PRINT_FP, NULL, > > > "%s", ...) > > > because otherwise you end up mixing strings and json format output in the > > > same result. > > > > > > You should be able to do > > > tc -j ... > > > and always get valid JSON output. > > > > > > One quick way to test json validation is to pipe it into python: > > > tc -j ... | python -mjson.tool > > > > Note that XDP has separate print functions for plain text and JSON, and > > the flow gets separated early on: > > > > mode = rta_getattr_u8(tb[IFLA_XDP_ATTACHED]); > > if (mode == XDP_ATTACHED_NONE) > > return; > > else if (is_json_context()) > > return details ? (void)0 : xdp_dump_json(tb); > > > > ... non-JSON handling follows... > > > > The use of fprintfs is therefore okay. Do you have a preference for > > using the wrapper, even if fprintf is safe? It's brevity vs > > consistency, I guess. We'd need a separate patch for that, 'cause I'm > > not touching all the fprintfs in the file, anyway. > > The only preference for the wrapper is that it is easy way to make > sure all code is JSON aware.
Yes... > Since fp is always stdout in current code, maybe just convert to printf. ...or maybe we could consider adding a wrapper for printf that wouldn't take all the unnecessary parameters print_string() takes, yet clearly indicate autor knows about JSON output concerns?
