ref: 9910099b383e28a0a8b9b8c26ea99a5a2d77f5b3
dir: /src/libc/stdlib/atexit.c/
#include <stdlib.h> #include <errno.h> #undef atexit int atexit(void (*fun)(void)) { if (_exitn == _ATEXIT_MAX) { errno = ENOMEM; return -1; } _exitf[_exitn++] = fun; return 0; }