ref: a4b082e87a11db4311b8b84224abfdb9dbad297a
dir: /lib/c/src/syscall.h/
extern void *_brk(void *addr); extern int _open(char *path, int flags, int perm); extern int _close(int fd); extern int _read(int fd, void *buf, size_t n); extern int _write(int fd, void *buf, size_t n); extern int _lseek(int fd, long off, int whence); extern void _Exit(int status); extern int raise(int sig); extern void (*signal(int sig, void (*func)(int)))(int);