/in/foo.c: In function 'main':
/in/foo.c:3:15: warning: implicit declaration of function 'scanf_s' [-Wimplicit-function-declaration]
 #define scanf scanf_s
               ^
/in/foo.c:19:2: note: in expansion of macro 'scanf'
  scanf("%d%d%d%d", &n, &m, &star,&eat);
  ^~~~~
/tmp/ccoVDp6a.o: In function `main':
foo.c:(.text.startup+0x46): undefined reference to `scanf_s'
foo.c:(.text.startup+0x90): undefined reference to `scanf_s'
collect2: error: ld returned 1 exit status