main.c: In function ‘use_quit’:
main.c:360:3: warning: ignoring return value of ‘write’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
  360 |   write (1, "\n(interrupt) Exiting bc.\n", 26);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
misc.c: In function ‘maybe_system’:
misc.c:108:15: warning: ignoring return value of ‘system’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
  108 |         (void)system(cmd);
      |               ^~~~~~~~~~~