$ cd /root/mrt && cc -O2 -Wall -pthread -o mfcrace mfcrace.c
mfcrace.c: In function 'main':
mfcrace.c:86:14: warning: unused variable 'n' [-Wunused-variable]
   int fd, rc, n = 0, secs = RUN_SECS, i;
             ^
$ ls -la mfcrace
-rwxr-xr-x  1 root  wheel  11392 Sep 10 09:18 /root/mrt/mfcrace
(exit 0)