add: if (ecaplay_mode == ECAPLAY_MODE_PL_PLAY) return get_track_playlist(n, argc, argv);
context: static const char* get_track(int n, int argc, char *argv[]){  int i, c = 0;  assert(n > 0 && n <= argc);  for(i = 1; i < argc; i++) {     /* FIXME: add support for '-- -foo.wav' */    if (argv[i][0] != '-') {      if (++c == n) {	return argv[i];      }    }  }   return NULL;}