/tmp/mship.c: In function 'main':
/tmp/mship.c:59:6: warning: implicit declaration of function 'sysctlbyname'; did you mean 'ttyname'? [-Wimplicit-function-declaration]
  if (sysctlbyname("net.netisr.ncpus", &ncpus, &slen, NULL, 0) != 0)
      ^~~~~~~~~~~~
      ttyname
BUILD-OK